diff --git a/mod/admin.php b/mod/admin.php
index 39c2e9341b..f8a75b7a2d 100644
--- a/mod/admin.php
+++ b/mod/admin.php
@@ -1200,7 +1200,9 @@ function admin_page_site_post(App $a)
 	 * @var $storagebackend \Friendica\Model\Storage\IStorage
 	 */
 	$storagebackend    = Strings::escapeTags(trim(defaults($_POST, 'storagebackend', '')));
-	StorageManager::setBackend($storagebackend);
+	if (!StorageManager::setBackend($storagebackend)) {
+		info(L10n::t('Invalid storage backend setting value.'));
+	}
 
 	// save storage backend form
 	if (!is_null($storagebackend) && $storagebackend != "") {
diff --git a/src/Core/Console/Storage.php b/src/Core/Console/Storage.php
index 52f453471e..ce89ce1e2c 100644
--- a/src/Core/Console/Storage.php
+++ b/src/Core/Console/Storage.php
@@ -28,9 +28,10 @@ Synopsis
         Set current storage backend
             name        storage backend to use. see "list".
     
-    bin/console storage move [table]
+    bin/console storage move [table] [-n 5000]
         Move stored data to current storage backend.
             table       one of "photo" or "attach". default to both
+            -n          limit of processed entry batch size
 HELP;
 		return $help;
 	}
@@ -49,36 +50,36 @@ HELP;
 			return -1;
 		}
 
-		switch($this->args[0]) {
-		case 'list':
-			return $this->do_list();
-			break;
-		case 'set':
-			return $this->do_set();
-			break;
-		case 'move':
-			return $this->do_move();
-			break;
+		switch ($this->args[0]) {
+			case 'list':
+				return $this->doList();
+				break;
+			case 'set':
+				return $this->doSet();
+				break;
+			case 'move':
+				return $this->doMove();
+				break;
 		}
 
 		$this->out(sprintf('Invalid action "%s"', $this->args[0]));
 		return -1;
 	}
 
-	protected function do_list()
+	protected function doList()
 	{
 		$rowfmt = ' %-3s | %-20s';
 		$current = StorageManager::getBackend();
 		$this->out(sprintf($rowfmt, 'Sel', 'Name'));
 		$this->out('-----------------------');
 		$isregisterd = false;
-		foreach(StorageManager::listBackends() as $name => $class) {
+		foreach (StorageManager::listBackends() as $name => $class) {
 			$issel = ' ';
 			if ($current === $class) {
 				$issel = '*';
 				$isregisterd = true;
 			};
-			$this->out(sprintf($rowfmt, $issel , $name ));
+			$this->out(sprintf($rowfmt, $issel, $name));
 		}
 
 		if ($current === '') {
@@ -92,7 +93,7 @@ HELP;
 		return 0;
 	}
 
-	protected function do_set()
+	protected function doSet()
 	{
 		if (count($this->args) !== 2) {
 			throw new CommandArgsException('Invalid arguments');
@@ -106,11 +107,15 @@ HELP;
 			return -1;
 		}
 
-		StorageManager::setBackend($class);
+		if (!StorageManager::setBackend($class)) {
+			$this->out($class . ' is not a valid backend storage class.');
+			return -1;
+		}
+
 		return 0;
 	}
 
-	protected function do_move()
+	protected function doMove()
 	{
 		$tables = null;
 		if (count($this->args) < 1 || count($this->args) > 2) {
@@ -126,7 +131,17 @@ HELP;
 		}
 
 		$current = StorageManager::getBackend();
-		$r = StorageManager::move($current, $tables);
-		$this->out(sprintf('Moved %d files', $r));
+		$total = 0;
+
+		do {
+			$moved = StorageManager::move($current, $tables, $this->getOption('n', 5000));
+			if ($moved) {
+				$this->out(date('[Y-m-d H:i:s] ') . sprintf('Moved %d files', $moved));
+			}
+
+			$total += $moved;
+		} while ($moved);
+
+		$this->out(sprintf(date('[Y-m-d H:i:s] ') . 'Moved %d files total', $total));
 	}
 }
diff --git a/src/Core/StorageManager.php b/src/Core/StorageManager.php
index ef6cef480a..0a8b35ce24 100644
--- a/src/Core/StorageManager.php
+++ b/src/Core/StorageManager.php
@@ -23,7 +23,7 @@ class StorageManager
 
 	private static function setup()
 	{
-		if (count(self::$backends)==0) {
+		if (count(self::$backends) == 0) {
 			self::$backends = Config::get('storage', 'backends', self::$default_backends);
 		}
 	}
@@ -54,12 +54,18 @@ class StorageManager
 	 * @brief Set current storage backend class
 	 *
 	 * @param string $class Backend class name
+	 * @return bool
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	public static function setBackend($class)
 	{
-		/// @todo Check that $class implements IStorage
+		if (!in_array('Friendica\Model\Storage\IStorage', class_implements($class))) {
+			return false;
+		}
+
 		Config::set('storage', 'class', $class);
+
+		return true;
 	}
 
 	/**
@@ -105,20 +111,20 @@ class StorageManager
 
 
 	/**
-	 * @brief Move resources to storage $dest
+	 * @brief Move up to 5000 resources to storage $dest
 	 *
 	 * Copy existing data to destination storage and delete from source.
 	 * This method cannot move to legacy in-table `data` field.
 	 *
-	 * @param string     $dest    Destination storage class name
-	 * @param array|null $tables  Tables to look in for resources. Optional, defaults to ['photo', 'attach']
-	 *
-	 * @throws \Exception
+	 * @param string     $destination Storage class name
+	 * @param array|null $tables      Tables to look in for resources. Optional, defaults to ['photo', 'attach']
+	 * @param int        $limit       Limit of the process batch size, defaults to 5000
 	 * @return int Number of moved resources
+	 * @throws \Exception
 	 */
-	public static function move($dest, $tables = null)
+	public static function move($destination, $tables = null, $limit = 5000)
 	{
-		if (is_null($dest) || empty($dest)) {
+		if (empty($destination)) {
 			throw new \Exception('Can\'t move to NULL storage backend');
 		}
 		
@@ -129,43 +135,42 @@ class StorageManager
 		$moved = 0;
 		foreach ($tables as $table) {
 			// Get the rows where backend class is not the destination backend class
-			$rr = DBA::select(
+			$resources = DBA::select(
 				$table, 
 				['id', 'data', 'backend-class', 'backend-ref'],
-				['`backend-class` IS NULL or `backend-class` != ?' , $dest ]
+				['`backend-class` IS NULL or `backend-class` != ?', $destination],
+				['limit' => $limit]
 			);
 
-			if (DBA::isResult($rr)) {
-				while($r = DBA::fetch($rr)) {
-					$id = $r['id'];
-					$data = $r['data'];
-					/** @var IStorage $backendClass */
-					$backendClass = $r['backend-class'];
-					$backendRef = $r['backend-ref'];
-					if (!is_null($backendClass) && $backendClass !== '') {
-						Logger::log("get data from old backend " .  $backendClass . " : " . $backendRef);
-						$data = $backendClass::get($backendRef);
-					}
-					
-					Logger::log("save data to new backend " . $dest);
-					/** @var IStorage $dest */
-					$ref = $dest::put($data);
-					Logger::log("saved data as " . $ref);
+			while ($resource = DBA::fetch($resources)) {
+				$id = $resource['id'];
+				$data = $resource['data'];
+				/** @var IStorage $backendClass */
+				$backendClass = $resource['backend-class'];
+				$backendRef = $resource['backend-ref'];
+				if (!empty($backendClass)) {
+					Logger::log("get data from old backend " . $backendClass . " : " . $backendRef);
+					$data = $backendClass::get($backendRef);
+				}
 
-					if ($ref !== '') {
-						Logger::log("update row");
-						$ru = DBA::update($table, ['backend-class' => $dest, 'backend-ref' => $ref, 'data' => ''], ['id' => $id]);
-						
-						if ($ru) {
-							if (!is_null($backendClass) && $backendClass !== '') {
-								Logger::log("delete data from old backend " . $backendClass . " : " . $backendRef);
-								$backendClass::delete($backendRef);
-							}
-							$moved++;
+				Logger::log("save data to new backend " . $destination);
+				/** @var IStorage $destination */
+				$ref = $destination::put($data);
+				Logger::log("saved data as " . $ref);
+
+				if ($ref !== '') {
+					Logger::log("update row");
+					if (DBA::update($table, ['backend-class' => $destination, 'backend-ref' => $ref, 'data' => ''], ['id' => $id])) {
+						if (!empty($backendClass)) {
+							Logger::log("delete data from old backend " . $backendClass . " : " . $backendRef);
+							$backendClass::delete($backendRef);
 						}
+						$moved++;
 					}
 				}
 			}
+
+			DBA::close($resources);
 		}
 
 		return $moved;
diff --git a/src/Database/DBA.php b/src/Database/DBA.php
index 832f0a444f..5211c09106 100644
--- a/src/Database/DBA.php
+++ b/src/Database/DBA.php
@@ -1484,7 +1484,7 @@ class DBA
 		}
 
 		$limit_string = '';
-		if (isset($params['limit']) && is_int($params['limit'])) {
+		if (isset($params['limit']) && is_numeric($params['limit'])) {
 			$limit_string = " LIMIT " . intval($params['limit']);
 		}
 
diff --git a/src/Worker/CronJobs.php b/src/Worker/CronJobs.php
index f723cf69f1..5ebe91cf40 100644
--- a/src/Worker/CronJobs.php
+++ b/src/Worker/CronJobs.php
@@ -35,54 +35,42 @@ class CronJobs
 
 		Logger::log("Starting cronjob " . $command, Logger::DEBUG);
 
-		// Call possible post update functions
-		// see src/Database/PostUpdate.php for more details
-		if ($command == 'post_update') {
-			PostUpdate::update();
-			return;
-		}
+		switch($command) {
+			case 'post_update':
+				PostUpdate::update();
+				break;
 
-		// update nodeinfo data
-		if ($command == 'nodeinfo') {
-			nodeinfo_cron();
-			return;
-		}
+			case 'nodeinfo':
+				nodeinfo_cron();
+				break;
 
-		// Expire and remove user entries
-		if ($command == 'expire_and_remove_users') {
-			self::expireAndRemoveUsers();
-			return;
-		}
+			case 'expire_and_remove_users':
+				self::expireAndRemoveUsers();
+				break;
 
-		if ($command == 'update_contact_birthdays') {
-			Contact::updateBirthdays();
-			return;
-		}
+			case 'update_contact_birthdays':
+				Contact::updateBirthdays();
+				break;
 
-		if ($command == 'update_photo_albums') {
-			self::updatePhotoAlbums();
-			return;
-		}
+			case 'update_photo_albums':
+				self::updatePhotoAlbums();
+				break;
 
-		// Clear cache entries
-		if ($command == 'clear_cache') {
-			self::clearCache($a);
-			return;
-		}
+			case 'clear_cache':
+				self::clearCache($a);
+				break;
 
-		// Repair missing Diaspora values in contacts
-		if ($command == 'repair_diaspora') {
-			self::repairDiaspora($a);
-			return;
-		}
+			case 'repair_diaspora':
+				self::repairDiaspora($a);
+				break;
 
-		// Repair entries in the database
-		if ($command == 'repair_database') {
-			self::repairDatabase();
-			return;
-		}
+			case 'repair_database':
+				self::repairDatabase();
+				break;
 
-		Logger::log("Xronjob " . $command . " is unknown.", Logger::DEBUG);
+			default:
+				Logger::log("Xronjob " . $command . " is unknown.", Logger::DEBUG);
+		}
 
 		return;
 	}