diff --git a/apps/files_encryption/hooks/hooks.php b/apps/files_encryption/hooks/hooks.php
index a6b7555b3768f88d28b915ec13e7c12a7ae8c655..f26eefa30e2d1a79098463f4f64fe92c00c66ffb 100644
--- a/apps/files_encryption/hooks/hooks.php
+++ b/apps/files_encryption/hooks/hooks.php
@@ -502,7 +502,7 @@ class Hooks {
 	public static function preDisable($params) {
 		if ($params['app'] === 'files_encryption') {
 
-			\OC_Preferences::deleteAppFromAllUsers('files_encryption');
+			\OC::$server->getConfig()->deleteAppFromAllUsers('files_encryption');
 
 			$session = new \OCA\Encryption\Session(new \OC\Files\View('/'));
 			$session->setInitialized(\OCA\Encryption\Session::NOT_INITIALIZED);
diff --git a/apps/files_encryption/lib/util.php b/apps/files_encryption/lib/util.php
index 42a7e20c87ffa6c80315b9847e0108b2f2325fd9..2b4a50d6e2bbf30da3b23dd68168c3216ce25620 100644
--- a/apps/files_encryption/lib/util.php
+++ b/apps/files_encryption/lib/util.php
@@ -225,7 +225,7 @@ class Util {
 	 */
 	public function recoveryEnabledForUser() {
 
-		$recoveryMode = \OC_Preferences::getValue($this->userId, 'files_encryption', 'recovery_enabled', '0');
+		$recoveryMode = \OC::$server->getConfig()->getUserValue($this->userId, 'files_encryption', 'recovery_enabled', '0');
 
 		return ($recoveryMode === '1') ? true : false;
 
@@ -239,7 +239,12 @@ class Util {
 	public function setRecoveryForUser($enabled) {
 
 		$value = $enabled ? '1' : '0';
-		return \OC_Preferences::setValue($this->userId, 'files_encryption', 'recovery_enabled', $value);
+		try {
+			\OC::$server->getConfig()->setUserValue($this->userId, 'files_encryption', 'recovery_enabled', $value);
+			return true;
+		} catch(\OCP\PreConditionNotMetException $e) {
+			return false;
+		}
 
 	}
 
@@ -1102,7 +1107,12 @@ class Util {
 		// convert to string if preCondition is set
 		$preCondition = ($preCondition === null) ? null : (string)$preCondition;
 
-		return \OC_Preferences::setValue($this->userId, 'files_encryption', 'migration_status', (string)$status, $preCondition);
+		try {
+			\OC::$server->getConfig()->setUserValue($this->userId, 'files_encryption', 'migration_status', (string)$status, $preCondition);
+			return true;
+		} catch(\OCP\PreConditionNotMetException $e) {
+			return false;
+		}
 
 	}
 
@@ -1154,9 +1164,9 @@ class Util {
 
 		$migrationStatus = false;
 		if (\OCP\User::userExists($this->userId)) {
-			$migrationStatus = \OC_Preferences::getValue($this->userId, 'files_encryption', 'migration_status');
+			$migrationStatus = \OC::$server->getConfig()->getUserValue($this->userId, 'files_encryption', 'migration_status', null);
 			if ($migrationStatus === null) {
-				\OC_Preferences::setValue($this->userId, 'files_encryption', 'migration_status', (string)self::MIGRATION_OPEN);
+				\OC::$server->getConfig()->setUserValue($this->userId, 'files_encryption', 'migration_status', (string)self::MIGRATION_OPEN);
 				$migrationStatus = self::MIGRATION_OPEN;
 			}
 		}
diff --git a/apps/files_encryption/tests/util.php b/apps/files_encryption/tests/util.php
index 8d9aba423cdf5d1d23e9afc75ec3bd392b093faf..2d58db2128c7bca14d7573ebaf9d39d35484bd83 100755
--- a/apps/files_encryption/tests/util.php
+++ b/apps/files_encryption/tests/util.php
@@ -617,7 +617,9 @@ class Test_Encryption_Util extends \OCA\Files_Encryption\Tests\TestCase {
 	 * @return boolean
 	 */
 	private function setMigrationStatus($status, $user) {
-		return \OC_Preferences::setValue($user, 'files_encryption', 'migration_status', (string)$status);
+		\OC::$server->getConfig()->setUserValue($user, 'files_encryption', 'migration_status', (string)$status);
+		// the update will definitely be executed -> return value is always true
+		return true;
 	}
 
 }
diff --git a/apps/files_trashbin/lib/trashbin.php b/apps/files_trashbin/lib/trashbin.php
index 661fc271dfc1522708824f4259e7d5fa5ccaeb81..b9d7a4aa6cf11a1edc6b0e98f6138b1e3df07cba 100644
--- a/apps/files_trashbin/lib/trashbin.php
+++ b/apps/files_trashbin/lib/trashbin.php
@@ -621,11 +621,13 @@ class Trashbin {
 	 * @return int available free space for trash bin
 	 */
 	private static function calculateFreeSpace($trashbinSize, $user) {
+		$config = \OC::$server->getConfig();
+
 		$softQuota = true;
-		$quota = \OC_Preferences::getValue($user, 'files', 'quota');
+		$quota = $config->getUserValue($user, 'files', 'quota', null);
 		$view = new \OC\Files\View('/' . $user);
 		if ($quota === null || $quota === 'default') {
-			$quota = \OC::$server->getAppConfig()->getValue('files', 'default_quota');
+			$quota = $config->getAppValue('files', 'default_quota', null);
 		}
 		if ($quota === null || $quota === 'none') {
 			$quota = \OC\Files\Filesystem::free_space('/');
diff --git a/apps/files_versions/lib/storage.php b/apps/files_versions/lib/storage.php
index 82e0ecc3e2f28f001537556593e819213fb66e02..3d30ada863aee520af505631df07fb99e96c3afb 100644
--- a/apps/files_versions/lib/storage.php
+++ b/apps/files_versions/lib/storage.php
@@ -479,15 +479,16 @@ class Storage {
 	 * Erase a file's versions which exceed the set quota
 	 */
 	private static function expire($filename, $versionsSize = null, $offset = 0) {
-		if(\OCP\Config::getSystemValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+		$config = \OC::$server->getConfig();
+		if($config->getSystemValue('files_versions', Storage::DEFAULTENABLED)=='true') {
 			list($uid, $filename) = self::getUidAndFilename($filename);
 			$versionsFileview = new \OC\Files\View('/'.$uid.'/files_versions');
 
 			// get available disk space for user
 			$softQuota = true;
-			$quota = \OC_Preferences::getValue($uid, 'files', 'quota');
+			$quota = $config->getUserValue($uid, 'files', 'quota', null);
 			if ( $quota === null || $quota === 'default') {
-				$quota = \OC::$server->getAppConfig()->getValue('files', 'default_quota');
+				$quota = $config->getAppValue('files', 'default_quota', null);
 			}
 			if ( $quota === null || $quota === 'none' ) {
 				$quota = \OC\Files\Filesystem::free_space('/');
diff --git a/lib/base.php b/lib/base.php
index a019e9a000962baf096d983249a0f271ce76123b..af2474c7d763fa8f047f3eda74d5084fe9e49e72 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -218,7 +218,7 @@ class OC {
 
 	public static function checkInstalled() {
 		// Redirect to installer if not installed
-		if (!\OC::$server->getConfig()->getSystemValue('installed', false) && OC::$SUBURI != '/index.php') {
+		if (!\OC::$server->getSystemConfig()->getValue('installed', false) && OC::$SUBURI != '/index.php') {
 			if (OC::$CLI) {
 				throw new Exception('Not installed');
 			} else {
@@ -231,12 +231,12 @@ class OC {
 
 	public static function checkSSL() {
 		// redirect to https site if configured
-		if (\OC::$server->getConfig()->getSystemValue('forcessl', false)) {
+		if (\OC::$server->getSystemConfig()->getValue('forcessl', false)) {
 			// Default HSTS policy
 			$header = 'Strict-Transport-Security: max-age=31536000';
 
 			// If SSL for subdomains is enabled add "; includeSubDomains" to the header
-			if(\OC::$server->getConfig()->getSystemValue('forceSSLforSubdomains', false)) {
+			if(\OC::$server->getSystemConfig()->getValue('forceSSLforSubdomains', false)) {
 				$header .= '; includeSubDomains';
 			}
 			header($header);
@@ -256,7 +256,7 @@ class OC {
 
 	public static function checkMaintenanceMode() {
 		// Allow ajax update script to execute without being stopped
-		if (\OC::$server->getConfig()->getSystemValue('maintenance', false) && OC::$SUBURI != '/core/ajax/update.php') {
+		if (\OC::$server->getSystemConfig()->getValue('maintenance', false) && OC::$SUBURI != '/core/ajax/update.php') {
 			// send http status 503
 			header('HTTP/1.1 503 Service Temporarily Unavailable');
 			header('Status: 503 Service Temporarily Unavailable');
@@ -273,7 +273,7 @@ class OC {
 	public static function checkSingleUserMode() {
 		$user = OC_User::getUserSession()->getUser();
 		$group = OC_Group::getManager()->get('admin');
-		if ($user && \OC::$server->getConfig()->getSystemValue('singleuser', false) && !$group->inGroup($user)) {
+		if ($user && \OC::$server->getSystemConfig()->getValue('singleuser', false) && !$group->inGroup($user)) {
 			// send http status 503
 			header('HTTP/1.1 503 Service Temporarily Unavailable');
 			header('Status: 503 Service Temporarily Unavailable');
@@ -303,11 +303,11 @@ class OC {
 	 */
 	public static function checkUpgrade($showTemplate = true) {
 		if (\OCP\Util::needUpgrade()) {
-			$config = \OC::$server->getConfig();
-			if ($showTemplate && !$config->getSystemValue('maintenance', false)) {
+			$systemConfig = \OC::$server->getSystemConfig();
+			if ($showTemplate && !$systemConfig->getValue('maintenance', false)) {
 				$version = OC_Util::getVersion();
-				$oldTheme = $config->getSystemValue('theme');
-				$config->setSystemValue('theme', '');
+				$oldTheme = $systemConfig->getValue('theme');
+				$systemConfig->setValue('theme', '');
 				OC_Util::addScript('config'); // needed for web root
 				OC_Util::addScript('update');
 				$tmpl = new OC_Template('', 'update.admin', 'guest');
@@ -361,7 +361,7 @@ class OC {
 		OC_Util::addVendorScript('moment/min/moment-with-locales');
 
 		// avatars
-		if (\OC::$server->getConfig()->getSystemValue('enable_avatars', true) === true) {
+		if (\OC::$server->getSystemConfig()->getValue('enable_avatars', true) === true) {
 			\OC_Util::addScript('placeholder');
 			\OC_Util::addVendorScript('blueimp-md5/js/md5');
 			\OC_Util::addScript('jquery.avatar');
@@ -557,10 +557,10 @@ class OC {
 		$sessionLifeTime = self::getSessionLifeTime();
 		@ini_set('gc_maxlifetime', (string)$sessionLifeTime);
 
-		$config = \OC::$server->getConfig();
+		$systemConfig = \OC::$server->getSystemConfig();
 
 		// User and Groups
-		if (!$config->getSystemValue("installed", false)) {
+		if (!$systemConfig->getValue("installed", false)) {
 			self::$server->getSession()->set('user_id', '');
 		}
 
@@ -583,14 +583,14 @@ class OC {
 		$tmpManager = \OC::$server->getTempManager();
 		register_shutdown_function(array($tmpManager, 'clean'));
 
-		if ($config->getSystemValue('installed', false) && !self::checkUpgrade(false)) {
-			if (\OC::$server->getAppConfig()->getValue('core', 'backgroundjobs_mode', 'ajax') == 'ajax') {
+		if ($systemConfig->getValue('installed', false) && !self::checkUpgrade(false)) {
+			if (\OC::$server->getConfig()->getAppValue('core', 'backgroundjobs_mode', 'ajax') == 'ajax') {
 				OC_Util::addScript('backgroundjobs');
 			}
 		}
 
 		// Check whether the sample configuration has been copied
-		if($config->getSystemValue('copied_sample_config', false)) {
+		if($systemConfig->getValue('copied_sample_config', false)) {
 			$l = \OC::$server->getL10N('lib');
 			header('HTTP/1.1 503 Service Temporarily Unavailable');
 			header('Status: 503 Service Temporarily Unavailable');
@@ -632,7 +632,7 @@ class OC {
 	 * register hooks for the cache
 	 */
 	public static function registerCacheHooks() {
-		if (\OC::$server->getConfig()->getSystemValue('installed', false) && !\OCP\Util::needUpgrade()) { //don't try to do this before we are properly setup
+		if (\OC::$server->getSystemConfig()->getValue('installed', false) && !\OCP\Util::needUpgrade()) { //don't try to do this before we are properly setup
 			\OCP\BackgroundJob::registerJob('OC\Cache\FileGlobalGC');
 
 			// NOTE: This will be replaced to use OCP
@@ -645,11 +645,11 @@ class OC {
 	 * register hooks for the cache
 	 */
 	public static function registerLogRotate() {
-		$config = \OC::$server->getConfig();
-		if ($config->getSystemValue('installed', false) && $config->getSystemValue('log_rotate_size', false) && !\OCP\Util::needUpgrade()) {
+		$systemConfig = \OC::$server->getSystemConfig();
+		if ($systemConfig->getValue('installed', false) && $systemConfig->getValue('log_rotate_size', false) && !\OCP\Util::needUpgrade()) {
 			//don't try to do this before we are properly setup
 			//use custom logfile path if defined, otherwise use default of owncloud.log in data directory
-			\OCP\BackgroundJob::registerJob('OC\Log\Rotate', $config->getSystemValue('logfile', $config->getSystemValue('datadirectory', OC::$SERVERROOT . '/data') . '/owncloud.log'));
+			\OCP\BackgroundJob::registerJob('OC\Log\Rotate', $systemConfig->getValue('logfile', $systemConfig->getValue('datadirectory', OC::$SERVERROOT . '/data') . '/owncloud.log'));
 		}
 	}
 
@@ -679,7 +679,7 @@ class OC {
 	 * register hooks for sharing
 	 */
 	public static function registerShareHooks() {
-		if (\OC::$server->getConfig()->getSystemValue('installed')) {
+		if (\OC::$server->getSystemConfig()->getValue('installed')) {
 			OC_Hook::connect('OC_User', 'post_deleteUser', 'OC\Share\Hooks', 'post_deleteUser');
 			OC_Hook::connect('OC_User', 'post_addToGroup', 'OC\Share\Hooks', 'post_addToGroup');
 			OC_Hook::connect('OC_User', 'post_removeFromGroup', 'OC\Share\Hooks', 'post_removeFromGroup');
@@ -694,7 +694,7 @@ class OC {
 		// generate an instanceid via \OC_Util::getInstanceId() because the
 		// config file may not be writable. As such, we only register a class
 		// loader cache if instanceid is available without trying to create one.
-		$instanceId = \OC::$server->getConfig()->getSystemValue('instanceid', null);
+		$instanceId = \OC::$server->getSystemConfig()->getValue('instanceid', null);
 		if ($instanceId) {
 			try {
 				$memcacheFactory = new \OC\Memcache\Factory($instanceId);
@@ -709,13 +709,13 @@ class OC {
 	 */
 	public static function handleRequest() {
 		\OC::$server->getEventLogger()->start('handle_request', 'Handle request');
-		$config = \OC::$server->getConfig();
+		$systemConfig = \OC::$server->getSystemConfig();
 		// load all the classpaths from the enabled apps so they are available
 		// in the routing files of each app
 		OC::loadAppClassPaths();
 
 		// Check if ownCloud is installed or in maintenance (update) mode
-		if (!$config->getSystemValue('installed', false)) {
+		if (!$systemConfig->getValue('installed', false)) {
 			\OC::$server->getSession()->clear();
 			$controller = new OC\Core\Setup\Controller(\OC::$server->getConfig());
 			$controller->run($_POST);
@@ -730,7 +730,7 @@ class OC {
 
 		if (!self::$CLI and (!isset($_GET["logout"]) or ($_GET["logout"] !== 'true'))) {
 			try {
-				if (!$config->getSystemValue('maintenance', false) && !\OCP\Util::needUpgrade()) {
+				if (!$systemConfig->getValue('maintenance', false) && !\OCP\Util::needUpgrade()) {
 					OC_App::loadApps(array('authentication'));
 					OC_App::loadApps(array('filesystem', 'logging'));
 					OC_App::loadApps();
@@ -796,7 +796,7 @@ class OC {
 			if (isset($_GET["logout"]) and ($_GET["logout"])) {
 				OC_JSON::callCheck();
 				if (isset($_COOKIE['oc_token'])) {
-					$config->deleteUserValue(OC_User::getUser(), 'login_token', $_COOKIE['oc_token']);
+					\OC::$server->getConfig()->deleteUserValue(OC_User::getUser(), 'login_token', $_COOKIE['oc_token']);
 				}
 				OC_User::logout();
 				// redirect to webroot and add slash if webroot is empty
diff --git a/lib/private/allconfig.php b/lib/private/allconfig.php
index 7ebff7cf2db8629d78f621c815ed353ea95122f8..e20f3698258b0263eb29fde92c5af631d64284b8 100644
--- a/lib/private/allconfig.php
+++ b/lib/private/allconfig.php
@@ -8,11 +8,67 @@
  */
 
 namespace OC;
+use OCP\IDBConnection;
+use OCP\PreConditionNotMetException;
 
 /**
  * Class to combine all the configuration options ownCloud offers
  */
 class AllConfig implements \OCP\IConfig {
+	/** @var SystemConfig */
+	private $systemConfig;
+
+	/** @var IDBConnection */
+	private $connection;
+
+	/**
+	 * 3 dimensional array with the following structure:
+	 * [ $userId =>
+	 *     [ $appId =>
+	 *         [ $key => $value ]
+	 *     ]
+	 * ]
+	 *
+	 * database table: preferences
+	 *
+	 * methods that use this:
+	 *   - setUserValue
+	 *   - getUserValue
+	 *   - getUserKeys
+	 *   - deleteUserValue
+	 *   - deleteAllUserValues
+	 *   - deleteAppFromAllUsers
+	 *
+	 * @var array $userCache
+	 */
+	private $userCache = array();
+
+	/**
+	 * @param SystemConfig $systemConfig
+	 */
+	function __construct(SystemConfig $systemConfig) {
+		$this->systemConfig = $systemConfig;
+	}
+
+	/**
+	 * TODO - FIXME This fixes an issue with base.php that cause cyclic
+	 * dependencies, especially with autoconfig setup
+	 *
+	 * Replace this by properly injected database connection. Currently the
+	 * base.php triggers the getDatabaseConnection too early which causes in
+	 * autoconfig setup case a too early distributed database connection and
+	 * the autoconfig then needs to reinit all already initialized dependencies
+	 * that use the database connection.
+	 *
+	 * otherwise a SQLite database is created in the wrong directory
+	 * because the database connection was created with an uninitialized config
+	 */
+	private function fixDIInit() {
+		if($this->connection === null) {
+			$this->connection = \OC::$server->getDatabaseConnection();
+		}
+	}
+
 	/**
 	 * Sets a new system wide value
 	 *
@@ -20,7 +76,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @param mixed $value the value that should be stored
 	 */
 	public function setSystemValue($key, $value) {
-		\OCP\Config::setSystemValue($key, $value);
+		$this->systemConfig->setValue($key, $value);
 	}
 
 	/**
@@ -31,7 +87,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @return mixed the value or $default
 	 */
 	public function getSystemValue($key, $default = '') {
-		return \OCP\Config::getSystemValue($key, $default);
+		return $this->systemConfig->getValue($key, $default);
 	}
 
 	/**
@@ -40,7 +96,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @param string $key the key of the value, under which it was saved
 	 */
 	public function deleteSystemValue($key) {
-		\OCP\Config::deleteSystemValue($key);
+		$this->systemConfig->deleteValue($key);
 	}
 
 	/**
@@ -61,7 +117,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @param string $value the value that should be stored
 	 */
 	public function setAppValue($appName, $key, $value) {
-		\OCP\Config::setAppValue($appName, $key, $value);
+		\OC::$server->getAppConfig()->setValue($appName, $key, $value);
 	}
 
 	/**
@@ -73,7 +129,7 @@ class AllConfig implements \OCP\IConfig {
 	 * @return string the saved value
 	 */
 	public function getAppValue($appName, $key, $default = '') {
-		return \OCP\Config::getAppValue($appName, $key, $default);
+		return \OC::$server->getAppConfig()->getValue($appName, $key, $default);
 	}
 
 	/**
@@ -83,7 +139,16 @@ class AllConfig implements \OCP\IConfig {
 	 * @param string $key the key of the value, under which it was saved
 	 */
 	public function deleteAppValue($appName, $key) {
-		\OC_Appconfig::deleteKey($appName, $key);
+		\OC::$server->getAppConfig()->deleteKey($appName, $key);
+	}
+
+	/**
+	 * Removes all keys in appconfig belonging to the app
+	 *
+	 * @param string $appName the appName the configs are stored under
+	 */
+	public function deleteAppValues($appName) {
+		\OC::$server->getAppConfig()->deleteApp($appName);
 	}
 
 
@@ -94,13 +159,60 @@ class AllConfig implements \OCP\IConfig {
 	 * @param string $appName the appName that we want to store the value under
 	 * @param string $key the key under which the value is being stored
 	 * @param string $value the value that you want to store
+	 * @param string $preCondition only update if the config value was previously the value passed as $preCondition
+	 * @throws \OCP\PreConditionNotMetException if a precondition is specified and is not met
 	 */
-	public function setUserValue($userId, $appName, $key, $value) {
-		\OCP\Config::setUserValue($userId, $appName, $key, $value);
+	public function setUserValue($userId, $appName, $key, $value, $preCondition = null) {
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		// Check if the key does exist
+		$sql  = 'SELECT `configvalue` FROM `*PREFIX*preferences` '.
+				'WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?';
+		$result = $this->connection->executeQuery($sql, array($userId, $appName, $key));
+		$oldValue = $result->fetchColumn();
+		$exists = $oldValue !== false;
+
+		if($oldValue === strval($value)) {
+			// no changes
+			return;
+		}
+
+		$data = array($value, $userId, $appName, $key);
+		if (!$exists && $preCondition === null) {
+			$sql  = 'INSERT INTO `*PREFIX*preferences` (`configvalue`, `userid`, `appid`, `configkey`)'.
+					'VALUES (?, ?, ?, ?)';
+		} elseif ($exists) {
+			$sql  = 'UPDATE `*PREFIX*preferences` SET `configvalue` = ? '.
+					'WHERE `userid` = ? AND `appid` = ? AND `configkey` = ? ';
+
+			if($preCondition !== null) {
+				if($this->getSystemValue('dbtype', 'sqlite') === 'oci') {
+					//oracle hack: need to explicitly cast CLOB to CHAR for comparison
+					$sql .= 'AND to_char(`configvalue`) = ?';
+				} else {
+					$sql .= 'AND `configvalue` = ?';
+				}
+				$data[] = $preCondition;
+			}
+		}
+		$affectedRows = $this->connection->executeUpdate($sql, $data);
+
+		// only add to the cache if we already loaded data for the user
+		if ($affectedRows > 0 && isset($this->userCache[$userId])) {
+			if (!isset($this->userCache[$userId][$appName])) {
+				$this->userCache[$userId][$appName] = array();
+			}
+			$this->userCache[$userId][$appName][$key] = $value;
+		}
+
+		if ($preCondition !== null && $affectedRows === 0) {
+			throw new PreConditionNotMetException;
+		}
 	}
 
 	/**
-	 * Shortcut for getting a user defined value
+	 * Getting a user defined value
 	 *
 	 * @param string $userId the userId of the user that we want to store the value under
 	 * @param string $appName the appName that we stored the value under
@@ -109,7 +221,12 @@ class AllConfig implements \OCP\IConfig {
 	 * @return string
 	 */
 	public function getUserValue($userId, $appName, $key, $default = '') {
-		return \OCP\Config::getUserValue($userId, $appName, $key, $default);
+		$data = $this->getUserValues($userId);
+		if (isset($data[$appName]) and isset($data[$appName][$key])) {
+			return $data[$appName][$key];
+		} else {
+			return $default;
+		}
 	}
 
 	/**
@@ -120,7 +237,12 @@ class AllConfig implements \OCP\IConfig {
 	 * @return string[]
 	 */
 	public function getUserKeys($userId, $appName) {
-		return \OC_Preferences::getKeys($userId, $appName);
+		$data = $this->getUserValues($userId);
+		if (isset($data[$appName])) {
+			return array_keys($data[$appName]);
+		} else {
+			return array();
+		}
 	}
 
 	/**
@@ -131,6 +253,153 @@ class AllConfig implements \OCP\IConfig {
 	 * @param string $key the key under which the value is being stored
 	 */
 	public function deleteUserValue($userId, $appName, $key) {
-		\OC_Preferences::deleteKey($userId, $appName, $key);
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		$sql  = 'DELETE FROM `*PREFIX*preferences` '.
+				'WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?';
+		$this->connection->executeUpdate($sql, array($userId, $appName, $key));
+
+		if (isset($this->userCache[$userId]) and isset($this->userCache[$userId][$appName])) {
+			unset($this->userCache[$userId][$appName][$key]);
+		}
+	}
+
+	/**
+	 * Delete all user values
+	 *
+	 * @param string $userId the userId of the user that we want to remove all values from
+	 */
+	public function deleteAllUserValues($userId) {
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		$sql  = 'DELETE FROM `*PREFIX*preferences` '.
+			'WHERE `userid` = ?';
+		$this->connection->executeUpdate($sql, array($userId));
+
+		unset($this->userCache[$userId]);
+	}
+
+	/**
+	 * Delete all user related values of one app
+	 *
+	 * @param string $appName the appName of the app that we want to remove all values from
+	 */
+	public function deleteAppFromAllUsers($appName) {
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		$sql  = 'DELETE FROM `*PREFIX*preferences` '.
+				'WHERE `appid` = ?';
+		$this->connection->executeUpdate($sql, array($appName));
+
+		foreach ($this->userCache as &$userCache) {
+			unset($userCache[$appName]);
+		}
+	}
+
+	/**
+	 * Returns all user configs sorted by app of one user
+	 *
+	 * @param string $userId the user ID to get the app configs from
+	 * @return array[] - 2 dimensional array with the following structure:
+	 *     [ $appId =>
+	 *         [ $key => $value ]
+	 *     ]
+	 */
+	private function getUserValues($userId) {
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		if (isset($this->userCache[$userId])) {
+			return $this->userCache[$userId];
+		}
+		$data = array();
+		$query = 'SELECT `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?';
+		$result = $this->connection->executeQuery($query, array($userId));
+		while ($row = $result->fetch()) {
+			$appId = $row['appid'];
+			if (!isset($data[$appId])) {
+				$data[$appId] = array();
+			}
+			$data[$appId][$row['configkey']] = $row['configvalue'];
+		}
+		$this->userCache[$userId] = $data;
+		return $data;
+	}
+
+	/**
+	 * Fetches a mapped list of userId -> value, for a specified app and key and a list of user IDs.
+	 *
+	 * @param $appName app to get the value for
+	 * @param $key the key to get the value for
+	 * @param $userIds the user IDs to fetch the values for
+	 * @return array Mapped values: userId => value
+	 */
+	public function getUserValueForUsers($appName, $key, $userIds) {
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		if (empty($userIds) || !is_array($userIds)) {
+			return array();
+		}
+
+		$chunkedUsers = array_chunk($userIds, 50, true);
+		$placeholders50 = implode(',', array_fill(0, 50, '?'));
+
+		$userValues = array();
+		foreach ($chunkedUsers as $chunk) {
+			$queryParams = $chunk;
+			// create [$app, $key, $chunkedUsers]
+			array_unshift($queryParams, $key);
+			array_unshift($queryParams, $appName);
+
+			$placeholders = (sizeof($chunk) == 50) ? $placeholders50 :  implode(',', array_fill(0, sizeof($chunk), '?'));
+
+			$query    = 'SELECT `userid`, `configvalue` ' .
+						'FROM `*PREFIX*preferences` ' .
+						'WHERE `appid` = ? AND `configkey` = ? ' .
+						'AND `userid` IN (' . $placeholders . ')';
+			$result = $this->connection->executeQuery($query, $queryParams);
+
+			while ($row = $result->fetch()) {
+				$userValues[$row['userid']] = $row['configvalue'];
+			}
+		}
+
+		return $userValues;
+	}
+
+	/**
+	 * Determines the users that have the given value set for a specific app-key-pair
+	 *
+	 * @param string $appName the app to get the user for
+	 * @param string $key the key to get the user for
+	 * @param string $value the value to get the user for
+	 * @return array of user IDs
+	 */
+	public function getUsersForUserValue($appName, $key, $value) {
+		// TODO - FIXME
+		$this->fixDIInit();
+
+		$sql  = 'SELECT `userid` FROM `*PREFIX*preferences` ' .
+				'WHERE `appid` = ? AND `configkey` = ? ';
+
+		if($this->getSystemValue('dbtype', 'sqlite') === 'oci') {
+			//oracle hack: need to explicitly cast CLOB to CHAR for comparison
+			$sql .= 'AND to_char(`configvalue`) = ?';
+		} else {
+			$sql .= 'AND `configvalue` = ?';
+		}
+
+		$result = $this->connection->executeQuery($sql, array($appName, $key, $value));
+
+		$userIDs = array();
+		while ($row = $result->fetch()) {
+			$userIDs[] = $row['userid'];
+		}
+
+		return $userIDs;
 	}
 }
diff --git a/lib/private/config.php b/lib/private/config.php
index cc07d6a1ed124baa4fafad20391bd285aafd0ee9..8544de34b720b904cd0ad1b165361ad1cd41ff62 100644
--- a/lib/private/config.php
+++ b/lib/private/config.php
@@ -39,24 +39,6 @@ class Config {
 		$this->debugMode = (defined('DEBUG') && DEBUG);
 	}
 
-	/**
-	 * Enables or disables the debug mode
-	 * @param bool $state True to enable, false to disable
-	 */
-	public function setDebugMode($state) {
-		$this->debugMode = $state;
-		$this->writeData();
-		$this->cache;
-	}
-
-	/**
-	 * Returns whether the debug mode is enabled or disabled
-	 * @return bool True when enabled, false otherwise
-	 */
-	public function isDebugMode() {
-		return $this->debugMode;
-	}
-
 	/**
 	 * Lists all available config keys
 	 * @return array an array of key names
diff --git a/lib/private/db/connectionfactory.php b/lib/private/db/connectionfactory.php
index 58043b3044037cc502fb704457cb37f6196b94f8..9c75baf887d4d8531a7ee03f6d1e1ad536868627 100644
--- a/lib/private/db/connectionfactory.php
+++ b/lib/private/db/connectionfactory.php
@@ -123,23 +123,23 @@ class ConnectionFactory {
 	/**
 	 * Create the connection parameters for the config
 	 *
-	 * @param \OCP\IConfig $config
+	 * @param \OC\SystemConfig $config
 	 * @return array
 	 */
 	public function createConnectionParams($config) {
-		$type = $config->getSystemValue('dbtype', 'sqlite');
+		$type = $config->getValue('dbtype', 'sqlite');
 
 		$connectionParams = array(
-			'user' => $config->getSystemValue('dbuser', ''),
-			'password' => $config->getSystemValue('dbpassword', ''),
+			'user' => $config->getValue('dbuser', ''),
+			'password' => $config->getValue('dbpassword', ''),
 		);
-		$name = $config->getSystemValue('dbname', 'owncloud');
+		$name = $config->getValue('dbname', 'owncloud');
 
 		if ($this->normalizeType($type) === 'sqlite3') {
-			$datadir = $config->getSystemValue("datadirectory", \OC::$SERVERROOT . '/data');
+			$datadir = $config->getValue("datadirectory", \OC::$SERVERROOT . '/data');
 			$connectionParams['path'] = $datadir . '/' . $name . '.db';
 		} else {
-			$host = $config->getSystemValue('dbhost', '');
+			$host = $config->getValue('dbhost', '');
 			if (strpos($host, ':')) {
 				// Host variable may carry a port or socket.
 				list($host, $portOrSocket) = explode(':', $host, 2);
@@ -153,11 +153,11 @@ class ConnectionFactory {
 			$connectionParams['dbname'] = $name;
 		}
 
-		$connectionParams['tablePrefix'] = $config->getSystemValue('dbtableprefix', 'oc_');
-		$connectionParams['sqlite.journal_mode'] = $config->getSystemValue('sqlite.journal_mode', 'WAL');
+		$connectionParams['tablePrefix'] = $config->getValue('dbtableprefix', 'oc_');
+		$connectionParams['sqlite.journal_mode'] = $config->getValue('sqlite.journal_mode', 'WAL');
 
 		//additional driver options, eg. for mysql ssl
-		$driverOptions = $config->getSystemValue('dbdriveroptions', null);
+		$driverOptions = $config->getValue('dbdriveroptions', null);
 		if ($driverOptions) {
 			$connectionParams['driverOptions'] = $driverOptions;
 		}
diff --git a/lib/private/httphelper.php b/lib/private/httphelper.php
index dfc1bcf47cd2f4c7738a4d7f80cf03cebf26759d..846825dee8de0b0fd9621b527621dfaef62441f2 100644
--- a/lib/private/httphelper.php
+++ b/lib/private/httphelper.php
@@ -8,16 +8,18 @@
 
 namespace OC;
 
+use \OCP\IConfig;
+
 class HTTPHelper {
 	const USER_AGENT = 'ownCloud Server Crawler';
 
-	/** @var \OC\AllConfig */
+	/** @var \OCP\IConfig */
 	private $config;
 
 	/**
-	 * @param \OC\AllConfig $config
+	 * @param \OCP\IConfig $config
 	 */
-	public function __construct(AllConfig $config) {
+	public function __construct(IConfig $config) {
 		$this->config = $config;
 	}
 
diff --git a/lib/private/legacy/preferences.php b/lib/private/legacy/preferences.php
index 4b68b0e69aa453021bc4ec4169f2fd47bb44c381..907aafbc915cbf6d1c3a83f4aefacb73a09d35fa 100644
--- a/lib/private/legacy/preferences.php
+++ b/lib/private/legacy/preferences.php
@@ -21,47 +21,23 @@
  *
  */
 
-OC_Preferences::$object = new \OC\Preferences(OC_DB::getConnection());
 /**
  * This class provides an easy way for storing user preferences.
- * @deprecated use \OC\Preferences instead
+ * @deprecated use \OCP\IConfig methods instead
  */
 class OC_Preferences{
-	public static $object;
-	/**
-	 * Get all users using the preferences
-	 * @return array an array of user ids
-	 *
-	 * This function returns a list of all users that have at least one entry
-	 * in the preferences table.
-	 */
-	public static function getUsers() {
-		return self::$object->getUsers();
-	}
-
-	/**
-	 * Get all apps of a user
-	 * @param string $user user
-	 * @return integer[] with app ids
-	 *
-	 * This function returns a list of all apps of the user that have at least
-	 * one entry in the preferences table.
-	 */
-	public static function getApps( $user ) {
-		return self::$object->getApps( $user );
-	}
-
 	/**
 	 * Get the available keys for an app
 	 * @param string $user user
 	 * @param string $app the app we are looking for
 	 * @return array an array of key names
+	 * @deprecated use getUserKeys of \OCP\IConfig instead
 	 *
 	 * This function gets all keys of an app of an user. Please note that the
 	 * values are not returned.
 	 */
 	public static function getKeys( $user, $app ) {
-		return self::$object->getKeys( $user, $app );
+		return \OC::$server->getConfig()->getUserKeys($user, $app);
 	}
 
 	/**
@@ -71,12 +47,13 @@ class OC_Preferences{
 	 * @param string $key key
 	 * @param string $default = null, default value if the key does not exist
 	 * @return string the value or $default
+	 * @deprecated use getUserValue of \OCP\IConfig instead
 	 *
 	 * This function gets a value from the preferences table. If the key does
 	 * not exist the default value will be returned
 	 */
 	public static function getValue( $user, $app, $key, $default = null ) {
-		return self::$object->getValue( $user, $app, $key, $default );
+		return \OC::$server->getConfig()->getUserValue($user, $app, $key, $default);
 	}
 
 	/**
@@ -87,12 +64,18 @@ class OC_Preferences{
 	 * @param string $value value
 	 * @param string $preCondition only set value if the key had a specific value before
 	 * @return bool true if value was set, otherwise false
+	 * @deprecated use setUserValue of \OCP\IConfig instead
 	 *
 	 * Adds a value to the preferences. If the key did not exist before, it
 	 * will be added automagically.
 	 */
 	public static function setValue( $user, $app, $key, $value, $preCondition = null ) {
-		return self::$object->setValue( $user, $app, $key, $value, $preCondition );
+		try {
+			\OC::$server->getConfig()->setUserValue($user, $app, $key, $value, $preCondition);
+			return true;
+		} catch(\OCP\PreConditionNotMetException $e) {
+			return false;
+		}
 	}
 
 	/**
@@ -100,24 +83,13 @@ class OC_Preferences{
 	 * @param string $user user
 	 * @param string $app app
 	 * @param string $key key
+	 * @return bool true
+	 * @deprecated use deleteUserValue of \OCP\IConfig instead
 	 *
 	 * Deletes a key.
 	 */
 	public static function deleteKey( $user, $app, $key ) {
-		self::$object->deleteKey( $user, $app, $key );
-		return true;
-	}
-
-	/**
-	 * Remove app of user from preferences
-	 * @param string $user user
-	 * @param string $app app
-	 * @return bool
-	 *
-	 * Removes all keys in preferences belonging to the app and the user.
-	 */
-	public static function deleteApp( $user, $app ) {
-		self::$object->deleteApp( $user, $app );
+		\OC::$server->getConfig()->deleteUserValue($user, $app, $key);
 		return true;
 	}
 
@@ -125,11 +97,12 @@ class OC_Preferences{
 	 * Remove user from preferences
 	 * @param string $user user
 	 * @return bool
+	 * @deprecated use deleteUser of \OCP\IConfig instead
 	 *
 	 * Removes all keys in preferences belonging to the user.
 	 */
 	public static function deleteUser( $user ) {
-		self::$object->deleteUser( $user );
+		\OC::$server->getConfig()->deleteAllUserValues($user);
 		return true;
 	}
 
@@ -137,11 +110,12 @@ class OC_Preferences{
 	 * Remove app from all users
 	 * @param string $app app
 	 * @return bool
+	 * @deprecated use deleteAppFromAllUsers of \OCP\IConfig instead
 	 *
 	 * Removes all keys in preferences belonging to the app.
 	 */
 	public static function deleteAppFromAllUsers( $app ) {
-		self::$object->deleteAppFromAllUsers( $app );
+		\OC::$server->getConfig()->deleteAppFromAllUsers($app);
 		return true;
 	}
 }
diff --git a/lib/private/ocs/cloud.php b/lib/private/ocs/cloud.php
index 3ced0af8ee129be2680857cf4a05bb861280f2fc..552aa96a26b2588354d7814f78c2802b9cb8885b 100644
--- a/lib/private/ocs/cloud.php
+++ b/lib/private/ocs/cloud.php
@@ -91,7 +91,7 @@ class OC_OCS_Cloud {
 	}
 
 	public static function getCurrentUser() {
-		$email=OC_Preferences::getValue(OC_User::getUser(), 'settings', 'email', '');
+		$email=\OC::$server->getConfig()->getUserValue(OC_User::getUser(), 'settings', 'email', '');
 		$data  = array(
 			'id' => OC_User::getUser(),
 			'display-name' => OC_User::getDisplayName(),
diff --git a/lib/private/preferences.php b/lib/private/preferences.php
index cdaa207449d8b2b186190d7cbbcc8190d8702c48..cd4a9fd1c19e398af49e0f51eea8e5b1c60fb28b 100644
--- a/lib/private/preferences.php
+++ b/lib/private/preferences.php
@@ -37,16 +37,14 @@
 namespace OC;
 
 use OCP\IDBConnection;
+use OCP\PreConditionNotMetException;
 
 
 /**
  * This class provides an easy way for storing user preferences.
+ * @deprecated use \OCP\IConfig methods instead
  */
 class Preferences {
-	/**
-	 * @var \OC\DB\Connection
-	 */
-	protected $conn;
 
 	/**
 	 * 3 dimensional array with the following structure:
@@ -60,65 +58,14 @@ class Preferences {
 	 */
 	protected $cache = array();
 
+	/** @var \OCP\IConfig */
+	protected $config;
+
 	/**
 	 * @param \OCP\IDBConnection $conn
 	 */
 	public function __construct(IDBConnection $conn) {
-		$this->conn = $conn;
-	}
-
-	/**
-	 * Get all users using the preferences
-	 * @return array an array of user ids
-	 *
-	 * This function returns a list of all users that have at least one entry
-	 * in the preferences table.
-	 */
-	public function getUsers() {
-		$query = 'SELECT DISTINCT `userid` FROM `*PREFIX*preferences`';
-		$result = $this->conn->executeQuery($query);
-
-		$users = array();
-		while ($userid = $result->fetchColumn()) {
-			$users[] = $userid;
-		}
-
-		return $users;
-	}
-
-	/**
-	 * @param string $user
-	 * @return array[]
-	 */
-	protected function getUserValues($user) {
-		if (isset($this->cache[$user])) {
-			return $this->cache[$user];
-		}
-		$data = array();
-		$query = 'SELECT `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?';
-		$result = $this->conn->executeQuery($query, array($user));
-		while ($row = $result->fetch()) {
-			$app = $row['appid'];
-			if (!isset($data[$app])) {
-				$data[$app] = array();
-			}
-			$data[$app][$row['configkey']] = $row['configvalue'];
-		}
-		$this->cache[$user] = $data;
-		return $data;
-	}
-
-	/**
-	 * Get all apps of an user
-	 * @param string $user user
-	 * @return integer[] with app ids
-	 *
-	 * This function returns a list of all apps of the user that have at least
-	 * one entry in the preferences table.
-	 */
-	public function getApps($user) {
-		$data = $this->getUserValues($user);
-		return array_keys($data);
+		$this->config = \OC::$server->getConfig();
 	}
 
 	/**
@@ -126,17 +73,13 @@ class Preferences {
 	 * @param string $user user
 	 * @param string $app the app we are looking for
 	 * @return array an array of key names
+	 * @deprecated use getUserKeys of \OCP\IConfig instead
 	 *
 	 * This function gets all keys of an app of an user. Please note that the
 	 * values are not returned.
 	 */
 	public function getKeys($user, $app) {
-		$data = $this->getUserValues($user);
-		if (isset($data[$app])) {
-			return array_keys($data[$app]);
-		} else {
-			return array();
-		}
+		return $this->config->getUserKeys($user, $app);
 	}
 
 	/**
@@ -146,17 +89,13 @@ class Preferences {
 	 * @param string $key key
 	 * @param string $default = null, default value if the key does not exist
 	 * @return string the value or $default
+	 * @deprecated use getUserValue of \OCP\IConfig instead
 	 *
 	 * This function gets a value from the preferences table. If the key does
 	 * not exist the default value will be returned
 	 */
 	public function getValue($user, $app, $key, $default = null) {
-		$data = $this->getUserValues($user);
-		if (isset($data[$app]) and isset($data[$app][$key])) {
-			return $data[$app][$key];
-		} else {
-			return $default;
-		}
+		return $this->config->getUserValue($user, $app, $key, $default);
 	}
 
 	/**
@@ -167,59 +106,18 @@ class Preferences {
 	 * @param string $value value
 	 * @param string $preCondition only set value if the key had a specific value before
 	 * @return bool true if value was set, otherwise false
+	 * @deprecated use setUserValue of \OCP\IConfig instead
 	 *
 	 * Adds a value to the preferences. If the key did not exist before, it
 	 * will be added automagically.
 	 */
 	public function setValue($user, $app, $key, $value, $preCondition = null) {
-		// Check if the key does exist
-		$query = 'SELECT `configvalue` FROM `*PREFIX*preferences`'
-			. ' WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?';
-		$oldValue = $this->conn->fetchColumn($query, array($user, $app, $key));
-		$exists = $oldValue !== false;
-
-		if($oldValue === strval($value)) {
-			// no changes
+		try {
+			$this->config->setUserValue($user, $app, $key, $value, $preCondition);
 			return true;
+		} catch(PreConditionNotMetException $e) {
+			return false;
 		}
-		
-		$affectedRows = 0;
-
-		if (!$exists && $preCondition === null) {
-			$data = array(
-				'userid' => $user,
-				'appid' => $app,
-				'configkey' => $key,
-				'configvalue' => $value,
-			);
-			$affectedRows = $this->conn->insert('*PREFIX*preferences', $data);
-		} elseif ($exists) {
-			$data = array($value, $user, $app, $key);
-			$sql  = "UPDATE `*PREFIX*preferences` SET `configvalue` = ?"
-					. " WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?";
-
-			if ($preCondition !== null) {
-				if (\OC_Config::getValue( 'dbtype', 'sqlite' ) === 'oci') {
-					//oracle hack: need to explicitly cast CLOB to CHAR for comparison
-					$sql .= " AND to_char(`configvalue`) = ?";
-				} else {
-					$sql .= " AND `configvalue` = ?";
-				}
-				$data[] = $preCondition;
-			}
-			$affectedRows = $this->conn->executeUpdate($sql, $data);
-		}
-
-		// only add to the cache if we already loaded data for the user
-		if ($affectedRows > 0 && isset($this->cache[$user])) {
-			if (!isset($this->cache[$user][$app])) {
-				$this->cache[$user][$app] = array();
-			}
-			$this->cache[$user][$app][$key] = $value;
-		}
-
-		return ($affectedRows > 0) ? true : false;
-
 	}
 
 	/**
@@ -228,35 +126,10 @@ class Preferences {
 	 * @param string $key
 	 * @param array $users
 	 * @return array Mapped values: userid => value
+	 * @deprecated use getUserValueForUsers of \OCP\IConfig instead
 	 */
 	public function getValueForUsers($app, $key, $users) {
-		if (empty($users) || !is_array($users)) {
-			return array();
-		}
-
-		$chunked_users = array_chunk($users, 50, true);
-		$placeholders_50 = implode(',', array_fill(0, 50, '?'));
-
-		$userValues = array();
-		foreach ($chunked_users as $chunk) {
-			$queryParams = $chunk;
-			array_unshift($queryParams, $key);
-			array_unshift($queryParams, $app);
-
-			$placeholders = (sizeof($chunk) == 50) ? $placeholders_50 : implode(',', array_fill(0, sizeof($chunk), '?'));
-
-			$query = 'SELECT `userid`, `configvalue` '
-				. ' FROM `*PREFIX*preferences` '
-				. ' WHERE `appid` = ? AND `configkey` = ?'
-				. ' AND `userid` IN (' . $placeholders . ')';
-			$result = $this->conn->executeQuery($query, $queryParams);
-
-			while ($row = $result->fetch()) {
-				$userValues[$row['userid']] = $row['configvalue'];
-			}
-		}
-
-		return $userValues;
+		return $this->config->getUserValueForUsers($app, $key, $users);
 	}
 
 	/**
@@ -265,28 +138,10 @@ class Preferences {
 	 * @param string $key
 	 * @param string $value
 	 * @return array
+	 * @deprecated use getUsersForUserValue of \OCP\IConfig instead
 	 */
 	public function getUsersForValue($app, $key, $value) {
-		$users = array();
-
-		$query = 'SELECT `userid` '
-			. ' FROM `*PREFIX*preferences` '
-			. ' WHERE `appid` = ? AND `configkey` = ? AND ';
-
-		if (\OC_Config::getValue( 'dbtype', 'sqlite' ) === 'oci') {
-			//FIXME oracle hack: need to explicitly cast CLOB to CHAR for comparison
-			$query .= ' to_char(`configvalue`)= ?';
-		} else {
-			$query .= ' `configvalue` = ?';
-		}
-
-		$result = $this->conn->executeQuery($query, array($app, $key, $value));
-
-		while ($row = $result->fetch()) {
-			$users[] = $row['userid'];
-		}
-
-		return $users;
+		return $this->config->getUsersForUserValue($app, $key, $value);
 	}
 
 	/**
@@ -294,72 +149,33 @@ class Preferences {
 	 * @param string $user user
 	 * @param string $app app
 	 * @param string $key key
+	 * @deprecated use deleteUserValue of \OCP\IConfig instead
 	 *
 	 * Deletes a key.
 	 */
 	public function deleteKey($user, $app, $key) {
-		$where = array(
-			'userid' => $user,
-			'appid' => $app,
-			'configkey' => $key,
-		);
-		$this->conn->delete('*PREFIX*preferences', $where);
-
-		if (isset($this->cache[$user]) and isset($this->cache[$user][$app])) {
-			unset($this->cache[$user][$app][$key]);
-		}
-	}
-
-	/**
-	 * Remove app of user from preferences
-	 * @param string $user user
-	 * @param string $app app
-	 *
-	 * Removes all keys in preferences belonging to the app and the user.
-	 */
-	public function deleteApp($user, $app) {
-		$where = array(
-			'userid' => $user,
-			'appid' => $app,
-		);
-		$this->conn->delete('*PREFIX*preferences', $where);
-
-		if (isset($this->cache[$user])) {
-			unset($this->cache[$user][$app]);
-		}
+		$this->config->deleteUserValue($user, $app, $key);
 	}
 
 	/**
 	 * Remove user from preferences
 	 * @param string $user user
+	 * @deprecated use deleteAllUserValues of \OCP\IConfig instead
 	 *
 	 * Removes all keys in preferences belonging to the user.
 	 */
 	public function deleteUser($user) {
-		$where = array(
-			'userid' => $user,
-		);
-		$this->conn->delete('*PREFIX*preferences', $where);
-
-		unset($this->cache[$user]);
+		$this->config->deleteAllUserValues($user);
 	}
 
 	/**
 	 * Remove app from all users
 	 * @param string $app app
+	 * @deprecated use deleteAppFromAllUsers of \OCP\IConfig instead
 	 *
 	 * Removes all keys in preferences belonging to the app.
 	 */
 	public function deleteAppFromAllUsers($app) {
-		$where = array(
-			'appid' => $app,
-		);
-		$this->conn->delete('*PREFIX*preferences', $where);
-
-		foreach ($this->cache as &$userCache) {
-			unset($userCache[$app]);
-		}
+		$this->config->deleteAppFromAllUsers($app);
 	}
 }
-
-require_once __DIR__ . '/legacy/' . basename(__FILE__);
diff --git a/lib/private/server.php b/lib/private/server.php
index 9dc8a32b7378caf70a392f6b53a6daa185f28680..ce21980c532b4d80247cd31ed642147569702986 100644
--- a/lib/private/server.php
+++ b/lib/private/server.php
@@ -167,8 +167,13 @@ class Server extends SimpleContainer implements IServerContainer {
 		$this->registerService('NavigationManager', function ($c) {
 			return new \OC\NavigationManager();
 		});
-		$this->registerService('AllConfig', function ($c) {
-			return new \OC\AllConfig();
+		$this->registerService('AllConfig', function (Server $c) {
+			return new \OC\AllConfig(
+				$c->getSystemConfig()
+			);
+		});
+		$this->registerService('SystemConfig', function ($c) {
+			return new \OC\SystemConfig();
 		});
 		$this->registerService('AppConfig', function ($c) {
 			return new \OC\AppConfig(\OC_DB::getConnection());
@@ -230,11 +235,12 @@ class Server extends SimpleContainer implements IServerContainer {
 		});
 		$this->registerService('DatabaseConnection', function (Server $c) {
 			$factory = new \OC\DB\ConnectionFactory();
-			$type = $c->getConfig()->getSystemValue('dbtype', 'sqlite');
+			$systemConfig = $c->getSystemConfig();
+			$type = $systemConfig->getValue('dbtype', 'sqlite');
 			if (!$factory->isValidType($type)) {
 				throw new \OC\DatabaseException('Invalid database type');
 			}
-			$connectionParams = $factory->createConnectionParams($c->getConfig());
+			$connectionParams = $factory->createConnectionParams($systemConfig);
 			$connection = $factory->getConnection($type, $connectionParams);
 			$connection->getConfiguration()->setSQLLogger($c->getQueryLogger());
 			return $connection;
@@ -445,6 +451,15 @@ class Server extends SimpleContainer implements IServerContainer {
 		return $this->query('AllConfig');
 	}
 
+	/**
+	 * For internal use only
+	 *
+	 * @return \OC\SystemConfig
+	 */
+	function getSystemConfig() {
+		return $this->query('SystemConfig');
+	}
+
 	/**
 	 * Returns the app config manager
 	 *
diff --git a/lib/private/share/mailnotifications.php b/lib/private/share/mailnotifications.php
index 2f704fb2b3cdf84e97440d3188534bb0f97f0cbd..342d3d5057af010dfd56f696c3cb3ec0562b6aec 100644
--- a/lib/private/share/mailnotifications.php
+++ b/lib/private/share/mailnotifications.php
@@ -79,7 +79,7 @@ class MailNotifications {
 
 		foreach ($recipientList as $recipient) {
 			$recipientDisplayName = \OCP\User::getDisplayName($recipient);
-			$to = \OC_Preferences::getValue($recipient, 'settings', 'email', '');
+			$to = \OC::$server->getConfig()->getUserValue($recipient, 'settings', 'email', '');
 
 			if ($to === '') {
 				$noMail[] = $recipientDisplayName;
diff --git a/lib/private/systemconfig.php b/lib/private/systemconfig.php
new file mode 100644
index 0000000000000000000000000000000000000000..ce6883e5ab3e824e8c167e4a99f1a862148163f6
--- /dev/null
+++ b/lib/private/systemconfig.php
@@ -0,0 +1,49 @@
+<?php
+/**
+ * Copyright (c) 2014 Morris Jobke <hey@morrisjobke.de>
+ *               2013 Bart Visscher <bartv@thisnet.nl>
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ *
+ */
+
+namespace OC;
+
+/**
+ * Class which provides access to the system config values stored in config.php
+ * Internal class for bootstrap only.
+ * fixes cyclic DI: AllConfig needs AppConfig needs Database needs AllConfig
+ */
+class SystemConfig {
+	/**
+	 * Sets a new system wide value
+	 *
+	 * @param string $key the key of the value, under which will be saved
+	 * @param mixed $value the value that should be stored
+	 */
+	public function setValue($key, $value) {
+		\OC_Config::setValue($key, $value);
+	}
+
+	/**
+	 * Looks up a system wide defined value
+	 *
+	 * @param string $key the key of the value, under which it was saved
+	 * @param mixed $default the default value to be returned if the value isn't set
+	 * @return mixed the value or $default
+	 */
+	public function getValue($key, $default = '') {
+		return \OC_Config::getValue($key, $default);
+	}
+
+	/**
+	 * Delete a system wide defined value
+	 *
+	 * @param string $key the key of the value, under which it was saved
+	 */
+	public function deleteValue($key) {
+		\OC_Config::deleteKey($key);
+	}
+}
diff --git a/lib/private/user/manager.php b/lib/private/user/manager.php
index 2403f45aa2f4a6f5ebe019b46323975ddafc3864..4fa3711e3b865bce24b8c23f328f39be7dc698c1 100644
--- a/lib/private/user/manager.php
+++ b/lib/private/user/manager.php
@@ -11,6 +11,7 @@ namespace OC\User;
 
 use OC\Hooks\PublicEmitter;
 use OCP\IUserManager;
+use OCP\IConfig;
 
 /**
  * Class Manager
@@ -37,14 +38,14 @@ class Manager extends PublicEmitter implements IUserManager {
 	private $cachedUsers = array();
 
 	/**
-	 * @var \OC\AllConfig $config
+	 * @var \OCP\IConfig $config
 	 */
 	private $config;
 
 	/**
-	 * @param \OC\AllConfig $config
+	 * @param \OCP\IConfig $config
 	 */
-	public function __construct($config = null) {
+	public function __construct(IConfig $config = null) {
 		$this->config = $config;
 		$cachedUsers = &$this->cachedUsers;
 		$this->listen('\OC\User', 'postDelete', function ($user) use (&$cachedUsers) {
diff --git a/lib/private/user/session.php b/lib/private/user/session.php
index 94abaca3e76b87c2dc5991dd2624fd2b0b21ce35..277aa1a047e8b58c48bf21377bf09f2ac1c8bcd9 100644
--- a/lib/private/user/session.php
+++ b/lib/private/user/session.php
@@ -211,15 +211,15 @@ class Session implements IUserSession, Emitter {
 		}
 
 		// get stored tokens
-		$tokens = \OC_Preferences::getKeys($uid, 'login_token');
+		$tokens = \OC::$server->getConfig()->getUserKeys($uid, 'login_token');
 		// test cookies token against stored tokens
 		if (!in_array($currentToken, $tokens, true)) {
 			return false;
 		}
 		// replace successfully used token with a new one
-		\OC_Preferences::deleteKey($uid, 'login_token', $currentToken);
+		\OC::$server->getConfig()->deleteUserValue($uid, 'login_token', $currentToken);
 		$newToken = \OC::$server->getSecureRandom()->getMediumStrengthGenerator()->generate(32);
-		\OC_Preferences::setValue($uid, 'login_token', $newToken, time());
+		\OC::$server->getConfig()->setUserValue($uid, 'login_token', $newToken, time());
 		$this->setMagicInCookie($user->getUID(), $newToken);
 
 		//login
diff --git a/lib/private/user/user.php b/lib/private/user/user.php
index ad85337f628368864b7514669ff47a8f1f9e61c3..00ded84f955612a9c1a8b6b08b837d67c4a8c377 100644
--- a/lib/private/user/user.php
+++ b/lib/private/user/user.php
@@ -11,6 +11,7 @@ namespace OC\User;
 
 use OC\Hooks\Emitter;
 use OCP\IUser;
+use OCP\IConfig;
 
 class User implements IUser {
 	/**
@@ -49,7 +50,7 @@ class User implements IUser {
 	private $lastLogin;
 
 	/**
-	 * @var \OC\AllConfig $config
+	 * @var \OCP\IConfig $config
 	 */
 	private $config;
 
@@ -57,9 +58,9 @@ class User implements IUser {
 	 * @param string $uid
 	 * @param \OC_User_Interface $backend
 	 * @param \OC\Hooks\Emitter $emitter
-	 * @param \OC\AllConfig $config
+	 * @param \OCP\IConfig $config
 	 */
-	public function __construct($uid, $backend, $emitter = null, $config = null) {
+	public function __construct($uid, $backend, $emitter = null, IConfig $config = null) {
 		$this->uid = $uid;
 		$this->backend = $backend;
 		$this->emitter = $emitter;
@@ -67,10 +68,11 @@ class User implements IUser {
 		if ($this->config) {
 			$enabled = $this->config->getUserValue($uid, 'core', 'enabled', 'true');
 			$this->enabled = ($enabled === 'true');
+			$this->lastLogin = $this->config->getUserValue($uid, 'login', 'lastLogin', 0);
 		} else {
 			$this->enabled = true;
+			$this->lastLogin = \OC::$server->getConfig()->getUserValue($uid, 'login', 'lastLogin', 0);
 		}
-		$this->lastLogin = \OC_Preferences::getValue($uid, 'login', 'lastLogin', 0);
 	}
 
 	/**
@@ -139,7 +141,7 @@ class User implements IUser {
 	 */
 	public function updateLastLoginTimestamp() {
 		$this->lastLogin = time();
-		\OC_Preferences::setValue(
+		\OC::$server->getConfig()->setUserValue(
 			$this->uid, 'login', 'lastLogin', $this->lastLogin);
 	}
 
@@ -162,7 +164,7 @@ class User implements IUser {
 				\OC_Group::removeFromGroup($this->uid, $i);
 			}
 			// Delete the user's keys in preferences
-			\OC_Preferences::deleteUser($this->uid);
+			\OC::$server->getConfig()->deleteAllUserValues($this->uid);
 
 			// Delete user files in /data/
 			\OC_Helper::rmdirr(\OC_User::getHome($this->uid));
diff --git a/lib/public/config.php b/lib/public/config.php
index 65dde39cdce25d797c46f24bc0867f977b63d650..70ff3a3fed038d1685638d36465eb7050fc45aaa 100644
--- a/lib/public/config.php
+++ b/lib/public/config.php
@@ -37,6 +37,7 @@ namespace OCP;
 /**
  * This class provides functions to read and write configuration data.
  * configuration can be on a system, application or user level
+ * @deprecated use methods of \OCP\IConfig
  */
 class Config {
 	/**
@@ -44,12 +45,13 @@ class Config {
 	 * @param string $key key
 	 * @param mixed $default = null default value
 	 * @return mixed the value or $default
+	 * @deprecated use method getSystemValue of \OCP\IConfig
 	 *
 	 * This function gets the value from config.php. If it does not exist,
 	 * $default will be returned.
 	 */
 	public static function getSystemValue( $key, $default = null ) {
-		return \OC_Config::getValue( $key, $default );
+		return \OC::$server->getConfig()->getSystemValue( $key, $default );
 	}
 
 	/**
@@ -57,13 +59,14 @@ class Config {
 	 * @param string $key key
 	 * @param mixed $value value
 	 * @return bool
+	 * @deprecated use method setSystemValue of \OCP\IConfig
 	 *
 	 * This function sets the value and writes the config.php. If the file can
 	 * not be written, false will be returned.
 	 */
 	public static function setSystemValue( $key, $value ) {
 		try {
-			\OC_Config::setValue( $key, $value );
+			\OC::$server->getConfig()->setSystemValue( $key, $value );
 		} catch (\Exception $e) {
 			return false;
 		}
@@ -73,11 +76,12 @@ class Config {
 	/**
 	 * Deletes a value from config.php
 	 * @param string $key key
+	 * @deprecated use method deleteSystemValue of \OCP\IConfig
 	 *
 	 * This function deletes the value from config.php.
 	 */
 	public static function deleteSystemValue( $key ) {
-		return \OC_Config::deleteKey( $key );
+		\OC::$server->getConfig()->deleteSystemValue( $key );
 	}
 
 	/**
@@ -86,12 +90,13 @@ class Config {
 	 * @param string $key key
 	 * @param string $default = null, default value if the key does not exist
 	 * @return string the value or $default
+	 * @deprecated use method getAppValue of \OCP\IConfig
 	 *
 	 * This function gets a value from the appconfig table. If the key does
 	 * not exist the default value will be returned
 	 */
 	public static function getAppValue( $app, $key, $default = null ) {
-		return \OC_Appconfig::getValue( $app, $key, $default );
+		return \OC::$server->getConfig()->getAppValue( $app, $key, $default );
 	}
 
 	/**
@@ -100,12 +105,13 @@ class Config {
 	 * @param string $key key
 	 * @param string $value value
 	 * @return boolean true/false
+	 * @deprecated use method setAppValue of \OCP\IConfig
 	 *
 	 * Sets a value. If the key did not exist before it will be created.
 	 */
 	public static function setAppValue( $app, $key, $value ) {
 		try {
-			\OC_Appconfig::setValue( $app, $key, $value );
+			\OC::$server->getConfig()->setAppValue( $app, $key, $value );
 		} catch (\Exception $e) {
 			return false;
 		}
@@ -119,12 +125,13 @@ class Config {
 	 * @param string $key key
 	 * @param string $default = null, default value if the key does not exist
 	 * @return string the value or $default
+	 * @deprecated use method getUserValue of \OCP\IConfig
 	 *
 	 * This function gets a value from the preferences table. If the key does
 	 * not exist the default value will be returned
 	 */
 	public static function getUserValue( $user, $app, $key, $default = null ) {
-		return \OC_Preferences::getValue( $user, $app, $key, $default );
+		return \OC::$server->getConfig()->getUserValue( $user, $app, $key, $default );
 	}
 
 	/**
@@ -134,13 +141,14 @@ class Config {
 	 * @param string $key key
 	 * @param string $value value
 	 * @return bool
+	 * @deprecated use method setUserValue of \OCP\IConfig
 	 *
 	 * Adds a value to the preferences. If the key did not exist before, it
 	 * will be added automagically.
 	 */
 	public static function setUserValue( $user, $app, $key, $value ) {
 		try {
-			\OC_Preferences::setValue( $user, $app, $key, $value );
+			\OC::$server->getConfig()->setUserValue( $user, $app, $key, $value );
 		} catch (\Exception $e) {
 			return false;
 		}
diff --git a/lib/public/iappconfig.php b/lib/public/iappconfig.php
index d43eb70ee0450c7f85fa5c087b480e0df6644fc6..cbd1a7e0573ede04986d2da71b156239dfcf6b70 100644
--- a/lib/public/iappconfig.php
+++ b/lib/public/iappconfig.php
@@ -26,6 +26,7 @@ interface IAppConfig {
 	 * @param string $key key
 	 * @param string $default = null, default value if the key does not exist
 	 * @return string the value or $default
+	 * @deprecated use method getAppValue of \OCP\IConfig
 	 *
 	 * This function gets a value from the appconfig table. If the key does
 	 * not exist the default value will be returned
@@ -37,8 +38,7 @@ interface IAppConfig {
 	 * @param string $app app
 	 * @param string $key key
 	 * @return bool
-	 *
-	 * Deletes a key.
+	 * @deprecated use method deleteAppValue of \OCP\IConfig
 	 */
 	public function deleteKey($app, $key);
 
@@ -46,6 +46,7 @@ interface IAppConfig {
 	 * Get the available keys for an app
 	 * @param string $app the app we are looking for
 	 * @return array an array of key names
+	 * @deprecated use method getAppKeys of \OCP\IConfig
 	 *
 	 * This function gets all keys of an app. Please note that the values are
 	 * not returned.
@@ -66,6 +67,7 @@ interface IAppConfig {
 	 * @param string $app app
 	 * @param string $key key
 	 * @param string $value value
+	 * @deprecated use method setAppValue of \OCP\IConfig
 	 *
 	 * Sets a value. If the key did not exist before it will be created.
 	 * @return void
@@ -85,6 +87,7 @@ interface IAppConfig {
 	 * Remove app from appconfig
 	 * @param string $app app
 	 * @return bool
+	 * @deprecated use method deleteAppValue of \OCP\IConfig
 	 *
 	 * Removes all keys in appconfig belonging to the app.
 	 */
diff --git a/lib/public/iconfig.php b/lib/public/iconfig.php
index 554fee5b22fddde07f60443c0613bbd0187887ef..fe0f1273a80d38f7cc77fc3df65cee668e825cd5 100644
--- a/lib/public/iconfig.php
+++ b/lib/public/iconfig.php
@@ -94,6 +94,13 @@ interface IConfig {
 	 */
 	public function deleteAppValue($appName, $key);
 
+	/**
+	 * Removes all keys in appconfig belonging to the app
+	 *
+	 * @param string $appName the appName the configs are stored under
+	 */
+	public function deleteAppValues($appName);
+
 
 	/**
 	 * Set a user defined value
@@ -102,9 +109,10 @@ interface IConfig {
 	 * @param string $appName the appName that we want to store the value under
 	 * @param string $key the key under which the value is being stored
 	 * @param string $value the value that you want to store
-	 * @return void
+	 * @param string $preCondition only update if the config value was previously the value passed as $preCondition
+	 * @throws \OCP\PreConditionNotMetException if a precondition is specified and is not met
 	 */
-	public function setUserValue($userId, $appName, $key, $value);
+	public function setUserValue($userId, $appName, $key, $value, $preCondition = null);
 
 	/**
 	 * Shortcut for getting a user defined value
@@ -117,6 +125,16 @@ interface IConfig {
 	 */
 	public function getUserValue($userId, $appName, $key, $default = '');
 
+	/**
+	 * Fetches a mapped list of userId -> value, for a specified app and key and a list of user IDs.
+	 *
+	 * @param $appName app to get the value for
+	 * @param $key the key to get the value for
+	 * @param $userIds the user IDs to fetch the values for
+	 * @return array Mapped values: userId => value
+	 */
+	public function getUserValueForUsers($appName, $key, $userIds);
+
 	/**
 	 * Get the keys of all stored by an app for the user
 	 *
@@ -134,4 +152,28 @@ interface IConfig {
 	 * @param string $key the key under which the value is being stored
 	 */
 	public function deleteUserValue($userId, $appName, $key);
+
+	/**
+	 * Delete all user values
+	 *
+	 * @param string $userId the userId of the user that we want to remove all values from
+	 */
+	public function deleteAllUserValues($userId);
+
+	/**
+	 * Delete all user related values of one app
+	 *
+	 * @param string $appName the appName of the app that we want to remove all values from
+	 */
+	public function deleteAppFromAllUsers($appName);
+
+	/**
+	 * Determines the users that have the given value set for a specific app-key-pair
+	 *
+	 * @param string $appName the app to get the user for
+	 * @param string $key the key to get the user for
+	 * @param string $value the value to get the user for
+	 * @return array of user IDs
+	 */
+	public function getUsersForUserValue($appName, $key, $value);
 }
diff --git a/lib/public/preconditionnotmetexception.php b/lib/public/preconditionnotmetexception.php
new file mode 100644
index 0000000000000000000000000000000000000000..ceba01a0b4b6e273c3bc16e60e2eebe7ba510127
--- /dev/null
+++ b/lib/public/preconditionnotmetexception.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ * ownCloud
+ *
+ * @author Morris Jobke
+ * @copyright 2014 Morris Jobke <hey@morrisjobke.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+// use OCP namespace for all classes that are considered public.
+// This means that they should be used by apps instead of the internal ownCloud classes
+namespace OCP;
+
+/**
+ * Exception if the precondition of the config update method isn't met
+ */
+class PreConditionNotMetException extends \Exception {}
diff --git a/settings/ajax/lostpassword.php b/settings/ajax/lostpassword.php
index 395ba31f92b3abbc3af916244e396118efdb442a..b0fb20c4a7e4f272493d416a292e92e2c8818308 100644
--- a/settings/ajax/lostpassword.php
+++ b/settings/ajax/lostpassword.php
@@ -8,7 +8,7 @@ $l = \OC::$server->getL10N('settings');
 // Get data
 if( isset( $_POST['email'] ) && OC_Mail::validateAddress($_POST['email']) ) {
 	$email=trim($_POST['email']);
-	OC_Preferences::setValue(OC_User::getUser(), 'settings', 'email', $email);
+	\OC::$server->getConfig()->setUserValue(OC_User::getUser(), 'settings', 'email', $email);
 	OC_JSON::success(array("data" => array( "message" => $l->t("Email saved") )));
 }else{
 	OC_JSON::error(array("data" => array( "message" => $l->t("Invalid email") )));
diff --git a/settings/ajax/setlanguage.php b/settings/ajax/setlanguage.php
index a3988db85bb18e9b0b44ea8df0219c2bcfe7bd2f..a83212927bfe3521fb8f804a91cebe8faba978ad 100644
--- a/settings/ajax/setlanguage.php
+++ b/settings/ajax/setlanguage.php
@@ -11,7 +11,7 @@ if( isset( $_POST['lang'] ) ) {
 	$languageCodes=OC_L10N::findAvailableLanguages();
 	$lang=$_POST['lang'];
 	if(array_search($lang, $languageCodes) or $lang === 'en') {
-		OC_Preferences::setValue( OC_User::getUser(), 'core', 'lang', $lang );
+		\OC::$server->getConfig()->setUserValue( OC_User::getUser(), 'core', 'lang', $lang );
 		OC_JSON::success(array("data" => array( "message" => $l->t("Language changed") )));
 	}else{
 		OC_JSON::error(array("data" => array( "message" => $l->t("Invalid request") )));
diff --git a/settings/ajax/setquota.php b/settings/ajax/setquota.php
index f19506a0456770089d4f2a1c93a6ec17690aa761..64a686e83d7a250418b4bc2e3266ac7ee26f7c27 100644
--- a/settings/ajax/setquota.php
+++ b/settings/ajax/setquota.php
@@ -27,7 +27,7 @@ if($quota !== 'none' and $quota !== 'default') {
 
 // Return Success story
 if($username) {
-	OC_Preferences::setValue($username, 'files', 'quota', $quota);
+	\OC::$server->getConfig()->setUserValue($username, 'files', 'quota', $quota);
 }else{//set the default quota when no username is specified
 	if($quota === 'default') {//'default' as default quota makes no sense
 		$quota='none';
diff --git a/settings/personal.php b/settings/personal.php
index bef800ae7f146e7128aefb13a7b4c4c3625b242f..f181c9cb2c117467b744c38c48cca9d4476d3ea5 100644
--- a/settings/personal.php
+++ b/settings/personal.php
@@ -9,6 +9,7 @@ OC_Util::checkLoggedIn();
 
 $defaults = new OC_Defaults(); // initialize themable default strings and urls
 $certificateManager = \OC::$server->getCertificateManager();
+$config = \OC::$server->getConfig();
 
 // Highlight navigation entry
 OC_Util::addScript( 'settings', 'personal' );
@@ -16,7 +17,7 @@ OC_Util::addStyle( 'settings', 'settings' );
 \OC_Util::addVendorScript('strengthify/jquery.strengthify');
 \OC_Util::addVendorStyle('strengthify/strengthify');
 \OC_Util::addScript('files', 'jquery.fileupload');
-if (\OC_Config::getValue('enable_avatars', true) === true) {
+if ($config->getSystemValue('enable_avatars', true) === true) {
 	\OC_Util::addVendorScript('jcrop/js/jquery.Jcrop');
 	\OC_Util::addVendorStyle('jcrop/css/jquery.Jcrop');
 }
@@ -26,9 +27,9 @@ OC_App::setActiveNavigationEntry( 'personal' );
 
 $storageInfo=OC_Helper::getStorageInfo('/');
 
-$email=OC_Preferences::getValue(OC_User::getUser(), 'settings', 'email', '');
+$email=$config->getUserValue(OC_User::getUser(), 'settings', 'email', '');
 
-$userLang=OC_Preferences::getValue( OC_User::getUser(), 'core', 'lang', OC_L10N::findLanguage() );
+$userLang=$config->getUserValue( OC_User::getUser(), 'core', 'lang', OC_L10N::findLanguage() );
 $languageCodes=OC_L10N::findAvailableLanguages();
 
 //check if encryption was enabled in the past
@@ -74,9 +75,9 @@ usort( $languages, function ($a, $b) {
 
 //links to clients
 $clients = array(
-	'desktop' => OC_Config::getValue('customclient_desktop', $defaults->getSyncClientUrl()),
-	'android' => OC_Config::getValue('customclient_android', $defaults->getAndroidClientUrl()),
-	'ios'     => OC_Config::getValue('customclient_ios', $defaults->getiOSClientUrl())
+	'desktop' => $config->getSystemValue('customclient_desktop', $defaults->getSyncClientUrl()),
+	'android' => $config->getSystemValue('customclient_android', $defaults->getAndroidClientUrl()),
+	'ios'     => $config->getSystemValue('customclient_ios', $defaults->getiOSClientUrl())
 );
 
 // Return template
@@ -95,7 +96,7 @@ $tmpl->assign('displayName', OC_User::getDisplayName());
 $tmpl->assign('enableDecryptAll' , $enableDecryptAll);
 $tmpl->assign('backupKeysExists' , $backupKeysExists);
 $tmpl->assign('filesStillEncrypted' , $filesStillEncrypted);
-$tmpl->assign('enableAvatars', \OC_Config::getValue('enable_avatars', true));
+$tmpl->assign('enableAvatars', $config->getSystemValue('enable_avatars', true));
 $tmpl->assign('avatarChangeSupported', OC_User::canUserChangeAvatar(OC_User::getUser()));
 $tmpl->assign('certs', $certificateManager->listCertificates());
 
diff --git a/settings/users.php b/settings/users.php
index 85f160a1552abaff07d7a8511748c9223fab09a6..3da8017b883db342490027c07e07b999bf85e442 100644
--- a/settings/users.php
+++ b/settings/users.php
@@ -21,6 +21,8 @@ $users = array();
 $userManager = \OC_User::getManager();
 $groupManager = \OC_Group::getManager();
 
+$config = \OC::$server->getConfig();
+
 $isAdmin = OC_User::isAdminUser(OC_User::getUser());
 
 $groupsInfo = new \OC\Group\MetaData(OC_User::getUser(), $isAdmin, $groupManager);
@@ -28,7 +30,7 @@ $groupsInfo->setSorting($groupsInfo::SORT_USERCOUNT);
 list($adminGroup, $groups) = $groupsInfo->get();
 
 $recoveryAdminEnabled = OC_App::isEnabled('files_encryption') &&
-					    OC_Appconfig::getValue( 'files_encryption', 'recoveryAdminEnabled' );
+					    $config->getAppValue( 'files_encryption', 'recoveryAdminEnabled', null );
 
 if($isAdmin) {
 	$accessibleUsers = OC_User::getDisplayNames('', 30);
@@ -59,7 +61,7 @@ $defaultQuotaIsUserDefined=array_search($defaultQuota, $quotaPreset)===false
 
 // load users and quota
 foreach($accessibleUsers as $uid => $displayName) {
-	$quota = OC_Preferences::getValue($uid, 'files', 'quota', 'default');
+	$quota = $config->getUserValue($uid, 'files', 'quota', 'default');
 	$isQuotaUserDefined = array_search($quota, $quotaPreset) === false
 		&& array_search($quota, array('none', 'default')) === false;
 
diff --git a/status.php b/status.php
index db5813814d0442b254bdfb79221b766bfe1deb9a..f7bdfe1fd5166c89992909ee8d3f8d1a51bdc9b7 100644
--- a/status.php
+++ b/status.php
@@ -25,8 +25,10 @@ try {
 
 	require_once 'lib/base.php';
 
-	$installed = OC_Config::getValue('installed') == 1;
-	$maintenance = OC_Config::getValue('maintenance', false);
+	$systemConfig = \OC::$server->getSystemConfig();
+
+	$installed = $systemConfig->getValue('installed') == 1;
+	$maintenance = $systemConfig->getValue('maintenance', false);
 	$values=array(
 		'installed'=>$installed,
 		'maintenance' => $maintenance,
diff --git a/tests/lib/allconfig.php b/tests/lib/allconfig.php
new file mode 100644
index 0000000000000000000000000000000000000000..7f8ad5ec22171edace56b3bd207e88b72a87748a
--- /dev/null
+++ b/tests/lib/allconfig.php
@@ -0,0 +1,422 @@
+<?php
+/**
+ * Copyright (c) 2014 Morris Jobke <hey@morrisjobke.de>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace Test;
+
+class TestAllConfig extends \Test\TestCase {
+
+	/** @var  \OCP\IDBConnection */
+	protected $connection;
+
+	protected function getConfig($systemConfig = null, $connection = null) {
+		if($this->connection === null) {
+			$this->connection = \OC::$server->getDatabaseConnection();
+		}
+		if($connection === null) {
+			$connection = $this->connection;
+		}
+		if($systemConfig === null) {
+			$systemConfig = $this->getMock('\OC\SystemConfig');
+		}
+		return new \OC\AllConfig($systemConfig, $connection);
+	}
+
+	public function testDeleteUserValue() {
+		$config = $this->getConfig();
+
+		// preparation - add something to the database
+		$this->connection->executeUpdate(
+			'INSERT INTO `*PREFIX*preferences` (`userid`, `appid`, ' .
+			'`configkey`, `configvalue`) VALUES (?, ?, ?, ?)',
+			array('userDelete', 'appDelete', 'keyDelete', 'valueDelete')
+		);
+
+		$config->deleteUserValue('userDelete', 'appDelete', 'keyDelete');
+
+		$result = $this->connection->executeQuery(
+				'SELECT COUNT(*) AS `count` FROM `*PREFIX*preferences` WHERE `userid` = ?',
+				array('userDelete')
+			)->fetch();
+		$actualCount = $result['count'];
+
+		$this->assertEquals(0, $actualCount, 'There was one value in the database and after the tests there should be no entry left.');
+	}
+
+	public function testSetUserValue() {
+		$selectAllSQL = 'SELECT `userid`, `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?';
+		$config = $this->getConfig();
+
+		$config->setUserValue('userSet', 'appSet', 'keySet', 'valueSet');
+
+		$result = $this->connection->executeQuery($selectAllSQL, array('userSet'))->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userSet',
+			'appid'       => 'appSet',
+			'configkey'   => 'keySet',
+			'configvalue' => 'valueSet'
+		), $result[0]);
+
+		// test if the method overwrites existing database entries
+		$config->setUserValue('userSet', 'appSet', 'keySet', 'valueSet2');
+
+		$result = $this->connection->executeQuery($selectAllSQL, array('userSet'))->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userSet',
+			'appid'       => 'appSet',
+			'configkey'   => 'keySet',
+			'configvalue' => 'valueSet2'
+		), $result[0]);
+
+		// cleanup - it therefore relies on the successful execution of the previous test
+		$config->deleteUserValue('userSet', 'appSet', 'keySet');
+	}
+
+	public function testSetUserValueWithPreCondition() {
+		// mock the check for the database to run the correct SQL statements for each database type
+		$systemConfig = $this->getMock('\OC\SystemConfig');
+		$systemConfig->expects($this->once())
+			->method('getValue')
+			->with($this->equalTo('dbtype'),
+				$this->equalTo('sqlite'))
+			->will($this->returnValue(\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite')));
+		$config = $this->getConfig($systemConfig);
+
+		$selectAllSQL = 'SELECT `userid`, `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?';
+
+		$config->setUserValue('userPreCond', 'appPreCond', 'keyPreCond', 'valuePreCond');
+
+		$result = $this->connection->executeQuery($selectAllSQL, array('userPreCond'))->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userPreCond',
+			'appid'       => 'appPreCond',
+			'configkey'   => 'keyPreCond',
+			'configvalue' => 'valuePreCond'
+		), $result[0]);
+
+		// test if the method overwrites existing database entries with valid precond
+		$config->setUserValue('userPreCond', 'appPreCond', 'keyPreCond', 'valuePreCond2', 'valuePreCond');
+
+		$result = $this->connection->executeQuery($selectAllSQL, array('userPreCond'))->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userPreCond',
+			'appid'       => 'appPreCond',
+			'configkey'   => 'keyPreCond',
+			'configvalue' => 'valuePreCond2'
+		), $result[0]);
+
+		// cleanup
+		$config->deleteUserValue('userPreCond', 'appPreCond', 'keyPreCond');
+	}
+
+	/**
+	 * @expectedException \OCP\PreConditionNotMetException
+	 */
+	public function testSetUserValueWithPreConditionFailure() {
+		// mock the check for the database to run the correct SQL statements for each database type
+		$systemConfig = $this->getMock('\OC\SystemConfig');
+		$systemConfig->expects($this->once())
+			->method('getValue')
+			->with($this->equalTo('dbtype'),
+				$this->equalTo('sqlite'))
+			->will($this->returnValue(\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite')));
+		$config = $this->getConfig($systemConfig);
+
+		$selectAllSQL = 'SELECT `userid`, `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?';
+
+		$config->setUserValue('userPreCond1', 'appPreCond', 'keyPreCond', 'valuePreCond');
+
+		$result = $this->connection->executeQuery($selectAllSQL, array('userPreCond1'))->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userPreCond1',
+			'appid'       => 'appPreCond',
+			'configkey'   => 'keyPreCond',
+			'configvalue' => 'valuePreCond'
+		), $result[0]);
+
+		// test if the method overwrites existing database entries with valid precond
+		$config->setUserValue('userPreCond1', 'appPreCond', 'keyPreCond', 'valuePreCond2', 'valuePreCond3');
+
+		$result = $this->connection->executeQuery($selectAllSQL, array('userPreCond1'))->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userPreCond1',
+			'appid'       => 'appPreCond',
+			'configkey'   => 'keyPreCond',
+			'configvalue' => 'valuePreCond'
+		), $result[0]);
+
+		// cleanup
+		$config->deleteUserValue('userPreCond1', 'appPreCond', 'keyPreCond');
+	}
+
+	public function testSetUserValueUnchanged() {
+		// TODO - FIXME until the dependency injection is handled properly (in AllConfig)
+		$this->markTestSkipped('Skipped because this is just testable if database connection can be injected');
+
+		$resultMock = $this->getMockBuilder('\Doctrine\DBAL\Driver\Statement')
+			->disableOriginalConstructor()->getMock();
+		$resultMock->expects($this->once())
+			->method('fetchColumn')
+			->will($this->returnValue('valueSetUnchanged'));
+
+		$connectionMock = $this->getMock('\OCP\IDBConnection');
+		$connectionMock->expects($this->once())
+			->method('executeQuery')
+			->with($this->equalTo('SELECT `configvalue` FROM `*PREFIX*preferences` '.
+					'WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?'),
+				$this->equalTo(array('userSetUnchanged', 'appSetUnchanged', 'keySetUnchanged')))
+			->will($this->returnValue($resultMock));
+		$connectionMock->expects($this->never())
+			->method('executeUpdate');
+
+		$config = $this->getConfig(null, $connectionMock);
+
+		$config->setUserValue('userSetUnchanged', 'appSetUnchanged', 'keySetUnchanged', 'valueSetUnchanged');
+	}
+
+	public function testGetUserValue() {
+		$config = $this->getConfig();
+
+		// setup - it therefore relies on the successful execution of the previous test
+		$config->setUserValue('userGet', 'appGet', 'keyGet', 'valueGet');
+		$value = $config->getUserValue('userGet', 'appGet', 'keyGet');
+
+		$this->assertEquals('valueGet', $value);
+
+		$result = $this->connection->executeQuery(
+			'SELECT `userid`, `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?',
+			array('userGet')
+		)->fetchAll();
+
+		$this->assertEquals(1, count($result));
+		$this->assertEquals(array(
+			'userid'      => 'userGet',
+			'appid'       => 'appGet',
+			'configkey'   => 'keyGet',
+			'configvalue' => 'valueGet'
+		), $result[0]);
+
+		// drop data from database - but the config option should be cached in the config object
+		$this->connection->executeUpdate('DELETE FROM `*PREFIX*preferences` WHERE `userid` = ?', array('userGet'));
+
+		// testing the caching mechanism
+		$value = $config->getUserValue('userGet', 'appGet', 'keyGet');
+
+		$this->assertEquals('valueGet', $value);
+
+		$result = $this->connection->executeQuery(
+			'SELECT `userid`, `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?',
+			array('userGet')
+		)->fetchAll();
+
+		$this->assertEquals(0, count($result));
+	}
+
+	public function testGetUserKeys() {
+		$config = $this->getConfig();
+
+		// preparation - add something to the database
+		$data = array(
+			array('userFetch', 'appFetch1', 'keyFetch1', 'value1'),
+			array('userFetch', 'appFetch1', 'keyFetch2', 'value2'),
+			array('userFetch', 'appFetch2', 'keyFetch3', 'value3'),
+			array('userFetch', 'appFetch1', 'keyFetch4', 'value4'),
+			array('userFetch', 'appFetch4', 'keyFetch1', 'value5'),
+			array('userFetch', 'appFetch5', 'keyFetch1', 'value6'),
+			array('userFetch2', 'appFetch', 'keyFetch1', 'value7')
+		);
+		foreach ($data as $entry) {
+			$this->connection->executeUpdate(
+				'INSERT INTO `*PREFIX*preferences` (`userid`, `appid`, ' .
+				'`configkey`, `configvalue`) VALUES (?, ?, ?, ?)',
+				$entry
+			);
+		}
+
+		$value = $config->getUserKeys('userFetch', 'appFetch1');
+		$this->assertEquals(array('keyFetch1', 'keyFetch2', 'keyFetch4'), $value);
+
+		$value = $config->getUserKeys('userFetch2', 'appFetch');
+		$this->assertEquals(array('keyFetch1'), $value);
+
+		// cleanup
+		$this->connection->executeUpdate('DELETE FROM `*PREFIX*preferences`');
+	}
+
+	public function testGetUserValueDefault() {
+		$config = $this->getConfig();
+
+		$this->assertEquals('', $config->getUserValue('userGetUnset', 'appGetUnset', 'keyGetUnset'));
+		$this->assertEquals(null, $config->getUserValue('userGetUnset', 'appGetUnset', 'keyGetUnset', null));
+		$this->assertEquals('foobar', $config->getUserValue('userGetUnset', 'appGetUnset', 'keyGetUnset', 'foobar'));
+	}
+
+	public function testGetUserValueForUsers() {
+		$config = $this->getConfig();
+
+		// preparation - add something to the database
+		$data = array(
+			array('userFetch1', 'appFetch2', 'keyFetch1', 'value1'),
+			array('userFetch2', 'appFetch2', 'keyFetch1', 'value2'),
+			array('userFetch3', 'appFetch2', 'keyFetch1', 3),
+			array('userFetch4', 'appFetch2', 'keyFetch1', 'value4'),
+			array('userFetch5', 'appFetch2', 'keyFetch1', 'value5'),
+			array('userFetch6', 'appFetch2', 'keyFetch1', 'value6'),
+			array('userFetch7', 'appFetch2', 'keyFetch1', 'value7')
+		);
+		foreach ($data as $entry) {
+			$this->connection->executeUpdate(
+				'INSERT INTO `*PREFIX*preferences` (`userid`, `appid`, ' .
+				'`configkey`, `configvalue`) VALUES (?, ?, ?, ?)',
+				$entry
+			);
+		}
+
+		$value = $config->getUserValueForUsers('appFetch2', 'keyFetch1',
+			array('userFetch1', 'userFetch2', 'userFetch3', 'userFetch5'));
+		$this->assertEquals(array(
+				'userFetch1' => 'value1',
+				'userFetch2' => 'value2',
+				'userFetch3' => 3,
+				'userFetch5' => 'value5'
+			), $value);
+
+		$value = $config->getUserValueForUsers('appFetch2', 'keyFetch1',
+			array('userFetch1', 'userFetch4', 'userFetch9'));
+		$this->assertEquals(array(
+			'userFetch1' => 'value1',
+			'userFetch4' => 'value4'
+		), $value, 'userFetch9 is an non-existent user and should not be shown.');
+
+		// cleanup
+		$this->connection->executeUpdate('DELETE FROM `*PREFIX*preferences`');
+	}
+
+	public function testDeleteAllUserValues() {
+		$config = $this->getConfig();
+
+		// preparation - add something to the database
+		$data = array(
+			array('userFetch3', 'appFetch1', 'keyFetch1', 'value1'),
+			array('userFetch3', 'appFetch1', 'keyFetch2', 'value2'),
+			array('userFetch3', 'appFetch2', 'keyFetch3', 'value3'),
+			array('userFetch3', 'appFetch1', 'keyFetch4', 'value4'),
+			array('userFetch3', 'appFetch4', 'keyFetch1', 'value5'),
+			array('userFetch3', 'appFetch5', 'keyFetch1', 'value6'),
+			array('userFetch4', 'appFetch2', 'keyFetch1', 'value7')
+		);
+		foreach ($data as $entry) {
+			$this->connection->executeUpdate(
+				'INSERT INTO `*PREFIX*preferences` (`userid`, `appid`, ' .
+				'`configkey`, `configvalue`) VALUES (?, ?, ?, ?)',
+				$entry
+			);
+		}
+
+		$config->deleteAllUserValues('userFetch3');
+
+		$result = $this->connection->executeQuery(
+			'SELECT COUNT(*) AS `count` FROM `*PREFIX*preferences`'
+		)->fetch();
+		$actualCount = $result['count'];
+
+		$this->assertEquals(1, $actualCount, 'After removing `userFetch3` there should be exactly 1 entry left.');
+
+		// cleanup
+		$this->connection->executeUpdate('DELETE FROM `*PREFIX*preferences`');
+	}
+
+	public function testDeleteAppFromAllUsers() {
+		$config = $this->getConfig();
+
+		// preparation - add something to the database
+		$data = array(
+			array('userFetch5', 'appFetch1', 'keyFetch1', 'value1'),
+			array('userFetch5', 'appFetch1', 'keyFetch2', 'value2'),
+			array('userFetch5', 'appFetch2', 'keyFetch3', 'value3'),
+			array('userFetch5', 'appFetch1', 'keyFetch4', 'value4'),
+			array('userFetch5', 'appFetch4', 'keyFetch1', 'value5'),
+			array('userFetch5', 'appFetch5', 'keyFetch1', 'value6'),
+			array('userFetch6', 'appFetch2', 'keyFetch1', 'value7')
+		);
+		foreach ($data as $entry) {
+			$this->connection->executeUpdate(
+				'INSERT INTO `*PREFIX*preferences` (`userid`, `appid`, ' .
+				'`configkey`, `configvalue`) VALUES (?, ?, ?, ?)',
+				$entry
+			);
+		}
+
+		$config->deleteAppFromAllUsers('appFetch1');
+
+		$result = $this->connection->executeQuery(
+			'SELECT COUNT(*) AS `count` FROM `*PREFIX*preferences`'
+		)->fetch();
+		$actualCount = $result['count'];
+
+		$this->assertEquals(4, $actualCount, 'After removing `appFetch1` there should be exactly 4 entries left.');
+
+		$config->deleteAppFromAllUsers('appFetch2');
+
+		$result = $this->connection->executeQuery(
+			'SELECT COUNT(*) AS `count` FROM `*PREFIX*preferences`'
+		)->fetch();
+		$actualCount = $result['count'];
+
+		$this->assertEquals(2, $actualCount, 'After removing `appFetch2` there should be exactly 2 entries left.');
+
+		// cleanup
+		$this->connection->executeUpdate('DELETE FROM `*PREFIX*preferences`');
+	}
+
+	public function testGetUsersForUserValue() {
+		// mock the check for the database to run the correct SQL statements for each database type
+		$systemConfig = $this->getMock('\OC\SystemConfig');
+		$systemConfig->expects($this->once())
+			->method('getValue')
+			->with($this->equalTo('dbtype'),
+				$this->equalTo('sqlite'))
+			->will($this->returnValue(\OC::$server->getConfig()->getSystemValue('dbtype', 'sqlite')));
+		$config = $this->getConfig($systemConfig);
+
+		// preparation - add something to the database
+		$data = array(
+			array('user1', 'appFetch9', 'keyFetch9', 'value9'),
+			array('user2', 'appFetch9', 'keyFetch9', 'value9'),
+			array('user3', 'appFetch9', 'keyFetch9', 'value8'),
+			array('user4', 'appFetch9', 'keyFetch8', 'value9'),
+			array('user5', 'appFetch8', 'keyFetch9', 'value9'),
+			array('user6', 'appFetch9', 'keyFetch9', 'value9'),
+		);
+		foreach ($data as $entry) {
+			$this->connection->executeUpdate(
+				'INSERT INTO `*PREFIX*preferences` (`userid`, `appid`, ' .
+				'`configkey`, `configvalue`) VALUES (?, ?, ?, ?)',
+				$entry
+			);
+		}
+
+		$value = $config->getUsersForUserValue('appFetch9', 'keyFetch9', 'value9');
+		$this->assertEquals(array('user1', 'user2', 'user6'), $value);
+
+		// cleanup
+		$this->connection->executeUpdate('DELETE FROM `*PREFIX*preferences`');
+	}
+
+}
diff --git a/tests/lib/app/infoparser.php b/tests/lib/app/infoparser.php
index 13c0b51e117e212e9543bf39a6f42787ca00bf2b..e291b616e8bde3759ff129c5f9eb1a5e3487ea21 100644
--- a/tests/lib/app/infoparser.php
+++ b/tests/lib/app/infoparser.php
@@ -19,7 +19,7 @@ class InfoParser extends \PHPUnit_Framework_TestCase {
 	private $parser;
 
 	public function setUp() {
-		$config = $this->getMockBuilder('\OC\AllConfig')
+		$config = $this->getMockBuilder('\OCP\IConfig')
 			->disableOriginalConstructor()->getMock();
 		$httpHelper = $this->getMockBuilder('\OC\HTTPHelper')
 			->setConstructorArgs(array($config))
diff --git a/tests/lib/config.php b/tests/lib/config.php
index 9dff3aab84f9bfc335deb2a2d3443532509d9003..6adba356a1c7cf12864f9061e6ded0fb5dfd1577 100644
--- a/tests/lib/config.php
+++ b/tests/lib/config.php
@@ -47,7 +47,6 @@ class Test_Config extends \Test\TestCase {
 	}
 
 	public function testSetValue() {
-		$this->config->setDebugMode(false);
 		$this->config->setValue('foo', 'moo');
 		$expectedConfig = $this->initialConfig;
 		$expectedConfig['foo'] = 'moo';
@@ -73,7 +72,6 @@ class Test_Config extends \Test\TestCase {
 	}
 
 	public function testDeleteKey() {
-		$this->config->setDebugMode(false);
 		$this->config->deleteKey('foo');
 		$expectedConfig = $this->initialConfig;
 		unset($expectedConfig['foo']);
@@ -85,37 +83,6 @@ class Test_Config extends \Test\TestCase {
 		$this->assertEquals($expected, $content);
 	}
 
-	public function testSetDebugMode() {
-		$this->config->setDebugMode(true);
-		$this->assertAttributeEquals($this->initialConfig, 'cache', $this->config);
-		$this->assertAttributeEquals(true, 'debugMode', $this->config);
-		$content = file_get_contents($this->configFile);
-		$expected = "<?php\ndefine('DEBUG',true);\n\$CONFIG = array (\n  'foo' => 'bar',\n  'beers' => \n  array (\n    0 => 'Appenzeller',\n  " .
-			"  1 => 'Guinness',\n    2 => 'Kölsch',\n  ),\n  'alcohol_free' => false,\n);\n";
-		$this->assertEquals($expected, $content);
-
-		$this->config->setDebugMode(false);
-		$this->assertAttributeEquals($this->initialConfig, 'cache', $this->config);
-		$this->assertAttributeEquals(false, 'debugMode', $this->config);
-		$content = file_get_contents($this->configFile);
-		$expected = "<?php\n\$CONFIG = array (\n  'foo' => 'bar',\n  'beers' => \n  array (\n    0 => 'Appenzeller',\n  " .
-			"  1 => 'Guinness',\n    2 => 'Kölsch',\n  ),\n  'alcohol_free' => false,\n);\n";
-		$this->assertEquals($expected, $content);
-	}
-
-	public function testIsDebugMode() {
-		// Default
-		$this->assertFalse($this->config->isDebugMode());
-
-		// Manually set to false
-		$this->config->setDebugMode(false);
-		$this->assertFalse($this->config->isDebugMode());
-
-		// Manually set to true
-		$this->config->setDebugMode(true);
-		$this->assertTrue($this->config->isDebugMode());
-	}
-
 	public function testConfigMerge() {
 		// Create additional config
 		$additionalConfig = '<?php $CONFIG=array("php53"=>"totallyOutdated");';
diff --git a/tests/lib/helperstorage.php b/tests/lib/helperstorage.php
index 9f3bd8824f7beef9e16fe9360df5d4483e54ab99..8b5f41fc94cb5c19ced115495c834bc4d479ce3e 100644
--- a/tests/lib/helperstorage.php
+++ b/tests/lib/helperstorage.php
@@ -45,7 +45,7 @@ class Test_Helper_Storage extends \Test\TestCase {
 
 		\OC_User::setUserId('');
 		\OC_User::deleteUser($this->user);
-		\OC_Preferences::deleteUser($this->user);
+		\OC::$server->getConfig()->deleteAllUserValues($this->user);
 
 		parent::tearDown();
 	}
diff --git a/tests/lib/httphelper.php b/tests/lib/httphelper.php
index eb58508f1583b33ed240011347d0f0a3557aaad5..1cc4232ab4b354fe9fb080bbce53fac9856b2496 100644
--- a/tests/lib/httphelper.php
+++ b/tests/lib/httphelper.php
@@ -8,7 +8,7 @@
 
 class TestHTTPHelper extends \Test\TestCase {
 
-	/** @var \OC\AllConfig*/
+	/** @var \OCP\IConfig*/
 	private $config;
 	/** @var \OC\HTTPHelper */
 	private $httpHelperMock;
@@ -16,7 +16,7 @@ class TestHTTPHelper extends \Test\TestCase {
 	protected function setUp() {
 		parent::setUp();
 
-		$this->config = $this->getMockBuilder('\OC\AllConfig')
+		$this->config = $this->getMockBuilder('\OCP\IConfig')
 			->disableOriginalConstructor()->getMock();
 		$this->httpHelperMock = $this->getMockBuilder('\OC\HTTPHelper')
 			->setConstructorArgs(array($this->config))
diff --git a/tests/lib/preferences-singleton.php b/tests/lib/preferences-singleton.php
deleted file mode 100644
index 01e15acdfe109d52492670eb889a83baef937557..0000000000000000000000000000000000000000
--- a/tests/lib/preferences-singleton.php
+++ /dev/null
@@ -1,176 +0,0 @@
-<?php
-/**
- * Copyright (c) 2013 Christopher Schäpers <christopher@schaepers.it>
- * Copyright (c) 2013 Bart Visscher <bartv@thisnet.nl>
- * This file is licensed under the Affero General Public License version 3 or
- * later.
- * See the COPYING-README file.
- */
-
-class Test_Preferences extends \Test\TestCase {
-	public static function setUpBeforeClass() {
-		parent::setUpBeforeClass();
-
-		$query = \OC_DB::prepare('INSERT INTO `*PREFIX*preferences` VALUES(?, ?, ?, ?)');
-		$query->execute(array("Someuser", "someapp", "somekey", "somevalue"));
-
-		$query->execute(array("Someuser", "getusersapp", "somekey", "somevalue"));
-		$query->execute(array("Anotheruser", "getusersapp", "somekey", "someothervalue"));
-		$query->execute(array("Anuser", "getusersapp", "somekey", "somevalue"));
-
-		$query->execute(array("Someuser", "getappsapp", "somekey", "somevalue"));
-
-		$query->execute(array("Someuser", "getkeysapp", "firstkey", "somevalue"));
-		$query->execute(array("Someuser", "getkeysapp", "anotherkey", "somevalue"));
-		$query->execute(array("Someuser", "getkeysapp", "key-tastic", "somevalue"));
-
-		$query->execute(array("Someuser", "getvalueapp", "key", "a value for a key"));
-
-		$query->execute(array("Deleteuser", "deleteapp", "deletekey", "somevalue"));
-		$query->execute(array("Deleteuser", "deleteapp", "somekey", "somevalue"));
-		$query->execute(array("Deleteuser", "someapp", "somekey", "somevalue"));
-	}
-
-	public static function tearDownAfterClass() {
-		$query = \OC_DB::prepare('DELETE FROM `*PREFIX*preferences` WHERE `userid` = ?');
-		$query->execute(array('Someuser'));
-		$query->execute(array('Anotheruser'));
-		$query->execute(array('Anuser'));
-
-		parent::tearDownAfterClass();
-	}
-
-	public function testGetUsers() {
-		$query = \OC_DB::prepare('SELECT DISTINCT `userid` FROM `*PREFIX*preferences`');
-		$result = $query->execute();
-		$expected = array();
-		while ($row = $result->fetchRow()) {
-			$expected[] = $row['userid'];
-		}
-
-		sort($expected);
-		$users = \OC_Preferences::getUsers();
-		sort($users);
-		$this->assertEquals($expected, $users);
-	}
-
-	public function testGetApps() {
-		$query = \OC_DB::prepare('SELECT DISTINCT `appid` FROM `*PREFIX*preferences` WHERE `userid` = ?');
-		$result = $query->execute(array('Someuser'));
-		$expected = array();
-		while ($row = $result->fetchRow()) {
-			$expected[] = $row['appid'];
-		}
-
-		sort($expected);
-		$apps = \OC_Preferences::getApps('Someuser');
-		sort($apps);
-		$this->assertEquals($expected, $apps);
-	}
-
-	public function testGetKeys() {
-		$query = \OC_DB::prepare('SELECT DISTINCT `configkey` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ?');
-		$result = $query->execute(array('Someuser', 'getkeysapp'));
-		$expected = array();
-		while ($row = $result->fetchRow()) {
-			$expected[] = $row['configkey'];
-		}
-
-		sort($expected);
-		$keys = \OC_Preferences::getKeys('Someuser', 'getkeysapp');
-		sort($keys);
-		$this->assertEquals($expected, $keys);
-	}
-
-	public function testGetValue() {
-		$this->assertNull(\OC_Preferences::getValue('nonexistant', 'nonexistant', 'nonexistant'));
-
-		$this->assertEquals('default', \OC_Preferences::getValue('nonexistant', 'nonexistant', 'nonexistant', 'default'));
-
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'getvalueapp', 'key'));
-		$row = $result->fetchRow();
-		$expected = $row['configvalue'];
-		$this->assertEquals($expected, \OC_Preferences::getValue('Someuser', 'getvalueapp', 'key'));
-	}
-
-	public function testSetValue() {
-		$this->assertTrue(\OC_Preferences::setValue('Someuser', 'setvalueapp', 'newkey', 'newvalue'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'setvalueapp', 'newkey'));
-		$row = $result->fetchRow();
-		$value = $row['configvalue'];
-		$this->assertEquals('newvalue', $value);
-
-		$this->assertTrue(\OC_Preferences::setValue('Someuser', 'setvalueapp', 'newkey', 'othervalue'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'setvalueapp', 'newkey'));
-		$row = $result->fetchRow();
-		$value = $row['configvalue'];
-		$this->assertEquals('othervalue', $value);
-	}
-
-	public function testSetValueWithPreCondition() {
-		// remove existing key
-		$this->assertTrue(\OC_Preferences::deleteKey('Someuser', 'setvalueapp', 'newkey'));
-
-		// add new preference with pre-condition should fails
-		$this->assertFalse(\OC_Preferences::setValue('Someuser', 'setvalueapp', 'newkey', 'newvalue', 'preCondition'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'setvalueapp', 'newkey'));
-		$row = $result->fetchRow();
-		$this->assertFalse($row);
-
-		// add new preference without pre-condition should insert the new value
-		$this->assertTrue(\OC_Preferences::setValue('Someuser', 'setvalueapp', 'newkey', 'newvalue'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'setvalueapp', 'newkey'));
-		$row = $result->fetchRow();
-		$value = $row['configvalue'];
-		$this->assertEquals('newvalue', $value);
-
-		// wrong pre-condition, value should stay the same
-		$this->assertFalse(\OC_Preferences::setValue('Someuser', 'setvalueapp', 'newkey', 'othervalue', 'preCondition'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'setvalueapp', 'newkey'));
-		$row = $result->fetchRow();
-		$value = $row['configvalue'];
-		$this->assertEquals('newvalue', $value);
-
-		// correct pre-condition, value should change
-		$this->assertTrue(\OC_Preferences::setValue('Someuser', 'setvalueapp', 'newkey', 'othervalue', 'newvalue'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Someuser', 'setvalueapp', 'newkey'));
-		$row = $result->fetchRow();
-		$value = $row['configvalue'];
-		$this->assertEquals('othervalue', $value);
-	}
-
-	public function testDeleteKey() {
-		$this->assertTrue(\OC_Preferences::deleteKey('Deleteuser', 'deleteapp', 'deletekey'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?');
-		$result = $query->execute(array('Deleteuser', 'deleteapp', 'deletekey'));
-		$this->assertEquals(0, count($result->fetchAll()));
-	}
-
-	public function testDeleteApp() {
-		$this->assertTrue(\OC_Preferences::deleteApp('Deleteuser', 'deleteapp'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ? AND `appid` = ?');
-		$result = $query->execute(array('Deleteuser', 'deleteapp'));
-		$this->assertEquals(0, count($result->fetchAll()));
-	}
-
-	public function testDeleteUser() {
-		$this->assertTrue(\OC_Preferences::deleteUser('Deleteuser'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?');
-		$result = $query->execute(array('Deleteuser'));
-		$this->assertEquals(0, count($result->fetchAll()));
-	}
-
-	public function testDeleteAppFromAllUsers() {
-		$this->assertTrue(\OC_Preferences::deleteAppFromAllUsers('someapp'));
-		$query = \OC_DB::prepare('SELECT `configvalue` FROM `*PREFIX*preferences` WHERE `appid` = ?');
-		$result = $query->execute(array('someapp'));
-		$this->assertEquals(0, count($result->fetchAll()));
-	}
-}
diff --git a/tests/lib/preferences.php b/tests/lib/preferences.php
deleted file mode 100644
index 193b1f8028020bad4cb6ea769b56edfbe9bbff44..0000000000000000000000000000000000000000
--- a/tests/lib/preferences.php
+++ /dev/null
@@ -1,241 +0,0 @@
-<?php
-/**
- * Copyright (c) 2013 Christopher Schäpers <christopher@schaepers.it>
- * Copyright (c) 2013 Bart Visscher <bartv@thisnet.nl>
- * This file is licensed under the Affero General Public License version 3 or
- * later.
- * See the COPYING-README file.
- */
-
-class Test_Preferences_Object extends \Test\TestCase {
-	public function testGetUsers()
-	{
-		$statementMock = $this->getMock('\Doctrine\DBAL\Statement', array(), array(), '', false);
-		$statementMock->expects($this->exactly(2))
-			->method('fetchColumn')
-			->will($this->onConsecutiveCalls('foo', false));
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->once())
-			->method('executeQuery')
-			->with($this->equalTo('SELECT DISTINCT `userid` FROM `*PREFIX*preferences`'))
-			->will($this->returnValue($statementMock));
-
-		$preferences = new OC\Preferences($connectionMock);
-		$apps = $preferences->getUsers();
-		$this->assertEquals(array('foo'), $apps);
-	}
-
-	public function testSetValue()
-	{
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->exactly(2))
-			->method('fetchColumn')
-			->with($this->equalTo('SELECT `configvalue` FROM `*PREFIX*preferences`'
-				.' WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?'),
-				$this->equalTo(array('grg', 'bar', 'foo')))
-			->will($this->onConsecutiveCalls(false, 'v1'));
-		$connectionMock->expects($this->once())
-			->method('insert')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'userid' => 'grg',
-						'appid' => 'bar',
-						'configkey' => 'foo',
-						'configvalue' => 'v1',
-					)
-				));
-		$connectionMock->expects($this->once())
-			->method('executeUpdate')
-			->with($this->equalTo("UPDATE `*PREFIX*preferences` SET `configvalue` = ?"
-						. " WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?"),
-				$this->equalTo(array('v2', 'grg', 'bar', 'foo'))
-				);
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->setValue('grg', 'bar', 'foo', 'v1');
-		$preferences->setValue('grg', 'bar', 'foo', 'v2');
-	}
-
-	public function testSetValueUnchanged() {
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->exactly(3))
-			->method('fetchColumn')
-			->with($this->equalTo('SELECT `configvalue` FROM `*PREFIX*preferences`'
-				.' WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?'),
-				$this->equalTo(array('grg', 'bar', 'foo')))
-			->will($this->onConsecutiveCalls(false, 'v1', 'v1'));
-		$connectionMock->expects($this->once())
-			->method('insert')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'userid' => 'grg',
-						'appid' => 'bar',
-						'configkey' => 'foo',
-						'configvalue' => 'v1',
-					)
-				));
-		$connectionMock->expects($this->never())
-			->method('executeUpdate');
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->setValue('grg', 'bar', 'foo', 'v1');
-		$preferences->setValue('grg', 'bar', 'foo', 'v1');
-		$preferences->setValue('grg', 'bar', 'foo', 'v1');
-	}
-
-	public function testSetValueUnchanged2() {
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->exactly(3))
-			->method('fetchColumn')
-			->with($this->equalTo('SELECT `configvalue` FROM `*PREFIX*preferences`'
-				.' WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?'),
-				$this->equalTo(array('grg', 'bar', 'foo')))
-			->will($this->onConsecutiveCalls(false, 'v1', 'v2'));
-		$connectionMock->expects($this->once())
-			->method('insert')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'userid' => 'grg',
-						'appid' => 'bar',
-						'configkey' => 'foo',
-						'configvalue' => 'v1',
-					)
-				));
-		$connectionMock->expects($this->once())
-			->method('executeUpdate')
-			->with($this->equalTo("UPDATE `*PREFIX*preferences` SET `configvalue` = ?"
-						. " WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?"),
-				$this->equalTo(array('v2', 'grg', 'bar', 'foo'))
-				);
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->setValue('grg', 'bar', 'foo', 'v1');
-		$preferences->setValue('grg', 'bar', 'foo', 'v2');
-		$preferences->setValue('grg', 'bar', 'foo', 'v2');
-	}
-
-	public function testGetUserValues()
-	{
-		$query = \OC_DB::prepare('INSERT INTO `*PREFIX*preferences` VALUES(?, ?, ?, ?)');
-		$query->execute(array('SomeUser', 'testGetUserValues', 'somekey', 'somevalue'));
-		$query->execute(array('AnotherUser', 'testGetUserValues', 'somekey', 'someothervalue'));
-		$query->execute(array('AUser', 'testGetUserValues', 'somekey', 'somevalue'));
-
-		$preferences = new OC\Preferences(\OC_DB::getConnection());
-		$users = array('SomeUser', 'AnotherUser', 'NoValueSet');
-
-		$values = $preferences->getValueForUsers('testGetUserValues', 'somekey', $users);
-		$this->assertUserValues($values);
-
-		// Add a lot of users so the array is chunked
-		for ($i = 1; $i <= 75; $i++) {
-			array_unshift($users, 'NoValueBefore#' . $i);
-			array_push($users, 'NoValueAfter#' . $i);
-		}
-
-		$values = $preferences->getValueForUsers('testGetUserValues', 'somekey', $users);
-		$this->assertUserValues($values);
-
-		// Clean DB after the test
-		$query = \OC_DB::prepare('DELETE FROM `*PREFIX*preferences` WHERE `appid` = ?');
-		$query->execute(array('testGetUserValues'));
-	}
-
-	protected function assertUserValues($values) {
-		$this->assertEquals(2, sizeof($values));
-
-		$this->assertArrayHasKey('SomeUser', $values);
-		$this->assertEquals('somevalue', $values['SomeUser']);
-
-		$this->assertArrayHasKey('AnotherUser', $values);
-		$this->assertEquals('someothervalue', $values['AnotherUser']);
-	}
-
-	public function testGetValueUsers()
-	{
-		// Prepare data
-		$query = \OC_DB::prepare('INSERT INTO `*PREFIX*preferences` VALUES(?, ?, ?, ?)');
-		$query->execute(array('SomeUser', 'testGetUsersForValue', 'somekey', 'somevalue'));
-		$query->execute(array('AnotherUser', 'testGetUsersForValue', 'somekey', 'someothervalue'));
-		$query->execute(array('AUser', 'testGetUsersForValue', 'somekey', 'somevalue'));
-
-		$preferences = new OC\Preferences(\OC_DB::getConnection());
-		$result = $preferences->getUsersForValue('testGetUsersForValue', 'somekey', 'somevalue');
-		sort($result);
-		$this->assertEquals(array('AUser', 'SomeUser'), $result);
-
-		// Clean DB after the test
-		$query = \OC_DB::prepare('DELETE FROM `*PREFIX*preferences` WHERE `appid` = ?');
-		$query->execute(array('testGetUsersForValue'));
-	}
-
-	public function testDeleteKey()
-	{
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->once())
-			->method('delete')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'userid' => 'grg',
-						'appid' => 'bar',
-						'configkey' => 'foo',
-					)
-				));
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->deleteKey('grg', 'bar', 'foo');
-	}
-
-	public function testDeleteApp()
-	{
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->once())
-			->method('delete')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'userid' => 'grg',
-						'appid' => 'bar',
-					)
-				));
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->deleteApp('grg', 'bar');
-	}
-
-	public function testDeleteUser()
-	{
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->once())
-			->method('delete')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'userid' => 'grg',
-					)
-				));
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->deleteUser('grg');
-	}
-
-	public function testDeleteAppFromAllUsers()
-	{
-		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);
-		$connectionMock->expects($this->once())
-			->method('delete')
-			->with($this->equalTo('*PREFIX*preferences'),
-				$this->equalTo(
-					array(
-						'appid' => 'bar',
-					)
-				));
-
-		$preferences = new OC\Preferences($connectionMock);
-		$preferences->deleteAppFromAllUsers('bar');
-	}
-}
diff --git a/tests/lib/user/session.php b/tests/lib/user/session.php
index 8d9d024197c48d7b8a22c34edb5c26c7fbb40850..aa1ea5841c0573c49c3fcd9796f4c643211e6c7c 100644
--- a/tests/lib/user/session.php
+++ b/tests/lib/user/session.php
@@ -234,7 +234,7 @@ class Session extends \Test\TestCase {
 
 		//prepare login token
 		$token = 'goodToken';
-		\OC_Preferences::setValue('foo', 'login_token', $token, time());
+		\OC::$server->getConfig()->setUserValue('foo', 'login_token', $token, time());
 
 		$userSession = $this->getMock(
 			'\OC\User\Session',
@@ -282,7 +282,7 @@ class Session extends \Test\TestCase {
 
 		//prepare login token
 		$token = 'goodToken';
-		\OC_Preferences::setValue('foo', 'login_token', $token, time());
+		\OC::$server->getConfig()->setUserValue('foo', 'login_token', $token, time());
 
 		$userSession = new \OC\User\Session($manager, $session);
 		$granted = $userSession->loginWithCookie('foo', 'badToken');
@@ -323,7 +323,7 @@ class Session extends \Test\TestCase {
 
 		//prepare login token
 		$token = 'goodToken';
-		\OC_Preferences::setValue('foo', 'login_token', $token, time());
+		\OC::$server->getConfig()->setUserValue('foo', 'login_token', $token, time());
 
 		$userSession = new \OC\User\Session($manager, $session);
 		$granted = $userSession->loginWithCookie('foo', $token);
diff --git a/tests/lib/user/user.php b/tests/lib/user/user.php
index 6aa7243a75ab8c513b18e482912f1d664adcdd24..a940d6eb627b9b2f9120d560c08481964ff1ff46 100644
--- a/tests/lib/user/user.php
+++ b/tests/lib/user/user.php
@@ -9,7 +9,6 @@
 
 namespace Test\User;
 
-use OC\AllConfig;
 use OC\Hooks\PublicEmitter;
 
 class User extends \Test\TestCase {
@@ -228,10 +227,19 @@ class User extends \Test\TestCase {
 			->method('implementsActions')
 			->will($this->returnValue(false));
 
-		$allConfig = new AllConfig();
+		$allConfig = $this->getMockBuilder('\OCP\IConfig')
+			->disableOriginalConstructor()
+			->getMock();
+		$allConfig->expects($this->any())
+			->method('getUserValue')
+			->will($this->returnValue(true));
+		$allConfig->expects($this->any())
+			->method('getSystemValue')
+			->with($this->equalTo('datadirectory'))
+			->will($this->returnValue('arbitrary/path'));
 
 		$user = new \OC\User\User('foo', $backend, null, $allConfig);
-		$this->assertEquals(\OC_Config::getValue("datadirectory", \OC::$SERVERROOT . "/data") . '/foo', $user->getHome());
+		$this->assertEquals('arbitrary/path/foo', $user->getHome());
 	}
 
 	public function testCanChangePassword() {
diff --git a/tests/lib/util.php b/tests/lib/util.php
index 1ddbd2aba2b86d176a261455a72e0400ff8d95b7..3bb4b47c09cb39cd4405cf2962ab40df07fb8f95 100644
--- a/tests/lib/util.php
+++ b/tests/lib/util.php
@@ -152,7 +152,7 @@ class Test_Util extends \Test\TestCase {
 	function testHomeStorageWrapperWithoutQuota() {
 		$user1 = $this->getUniqueID();
 		\OC_User::createUser($user1, 'test');
-		OC_Preferences::setValue($user1, 'files', 'quota', 'none');
+		\OC::$server->getConfig()->setUserValue($user1, 'files', 'quota', 'none');
 		\OC_User::setUserId($user1);
 
 		\OC_Util::setupFS($user1);
@@ -164,7 +164,7 @@ class Test_Util extends \Test\TestCase {
 		// clean up
 		\OC_User::setUserId('');
 		\OC_User::deleteUser($user1);
-		OC_Preferences::deleteUser($user1);
+		\OC::$server->getConfig()->deleteAllUserValues($user1);
 		\OC_Util::tearDownFS();
 	}
 
@@ -174,7 +174,7 @@ class Test_Util extends \Test\TestCase {
 	function testHomeStorageWrapperWithQuota() {
 		$user1 = $this->getUniqueID();
 		\OC_User::createUser($user1, 'test');
-		OC_Preferences::setValue($user1, 'files', 'quota', '1024');
+		\OC::$server->getConfig()->setUserValue($user1, 'files', 'quota', '1024');
 		\OC_User::setUserId($user1);
 
 		\OC_Util::setupFS($user1);
@@ -191,7 +191,7 @@ class Test_Util extends \Test\TestCase {
 		// clean up
 		\OC_User::setUserId('');
 		\OC_User::deleteUser($user1);
-		OC_Preferences::deleteUser($user1);
+		\OC::$server->getConfig()->deleteAllUserValues($user1);
 		\OC_Util::tearDownFS();
 	}