diff --git a/apps/dav/lib/connector/sabre/filesplugin.php b/apps/dav/lib/connector/sabre/filesplugin.php
index 686d0863f9..dd4670da5f 100644
--- a/apps/dav/lib/connector/sabre/filesplugin.php
+++ b/apps/dav/lib/connector/sabre/filesplugin.php
@@ -39,6 +39,7 @@ use Sabre\DAV\Tree;
 use \Sabre\HTTP\RequestInterface;
 use \Sabre\HTTP\ResponseInterface;
 use OCP\Files\StorageNotAvailableException;
+use OCP\IConfig;
 
 class FilesPlugin extends ServerPlugin {
 
@@ -55,6 +56,7 @@ class FilesPlugin extends ServerPlugin {
 	const OWNER_ID_PROPERTYNAME = '{http://owncloud.org/ns}owner-id';
 	const OWNER_DISPLAY_NAME_PROPERTYNAME = '{http://owncloud.org/ns}owner-display-name';
 	const CHECKSUMS_PROPERTYNAME = '{http://owncloud.org/ns}checksums';
+	const DATA_FINGERPRINT_PROPERTYNAME = '{http://owncloud.org/ns}data-fingerprint';
 
 	/**
 	 * Reference to main server object
@@ -86,6 +88,11 @@ class FilesPlugin extends ServerPlugin {
 	 */
 	private $downloadAttachment;
 
+	/**
+	 * @var IConfig
+	 */
+	private $config;
+
 	/**
 	 * @param Tree $tree
 	 * @param View $view
@@ -94,10 +101,12 @@ class FilesPlugin extends ServerPlugin {
 	 */
 	public function __construct(Tree $tree,
 								View $view,
+								IConfig $config,
 								$isPublic = false,
 								$downloadAttachment = true) {
 		$this->tree = $tree;
 		$this->fileView = $view;
+		$this->config = $config;
 		$this->isPublic = $isPublic;
 		$this->downloadAttachment = $downloadAttachment;
 	}
@@ -125,6 +134,7 @@ class FilesPlugin extends ServerPlugin {
 		$server->protectedProperties[] = self::OWNER_ID_PROPERTYNAME;
 		$server->protectedProperties[] = self::OWNER_DISPLAY_NAME_PROPERTYNAME;
 		$server->protectedProperties[] = self::CHECKSUMS_PROPERTYNAME;
+		$server->protectedProperties[] = self::DATA_FINGERPRINT_PROPERTYNAME;
 
 		// normally these cannot be changed (RFC4918), but we want them modifiable through PROPPATCH
 		$allowedProperties = ['{DAV:}getetag'];
@@ -272,6 +282,18 @@ class FilesPlugin extends ServerPlugin {
 				$displayName = $owner->getDisplayName();
 				return $displayName;
 			});
+
+			$propFind->handle(self::DATA_FINGERPRINT_PROPERTYNAME, function() use ($node) {
+				if ($node->getPath() === '/') {
+					return $this->config->getSystemValue('data-fingerprint', '');
+				}
+			});
+		}
+
+		if ($node instanceof \OCA\DAV\Files\FilesHome) {
+			$propFind->handle(self::DATA_FINGERPRINT_PROPERTYNAME, function() use ($node) {
+				return $this->config->getSystemValue('data-fingerprint', '');
+			});
 		}
 
 		if ($node instanceof \OCA\DAV\Connector\Sabre\File) {
diff --git a/apps/dav/lib/connector/sabre/serverfactory.php b/apps/dav/lib/connector/sabre/serverfactory.php
index cab7a85d19..5853370778 100644
--- a/apps/dav/lib/connector/sabre/serverfactory.php
+++ b/apps/dav/lib/connector/sabre/serverfactory.php
@@ -137,8 +137,15 @@ class ServerFactory {
 			}
 			$objectTree->init($root, $view, $this->mountManager);
 
-			$server->addPlugin(new \OCA\DAV\Connector\Sabre\FilesPlugin($objectTree, $view, false,
-				!$this->config->getSystemValue('debug', false)));
+			$server->addPlugin(
+				new \OCA\DAV\Connector\Sabre\FilesPlugin(
+					$objectTree,
+					$view,
+					$this->config,
+					false,
+					!$this->config->getSystemValue('debug', false)
+				)
+			);
 			$server->addPlugin(new \OCA\DAV\Connector\Sabre\QuotaPlugin($view));
 
 			if($this->userSession->isLoggedIn()) {
diff --git a/apps/dav/lib/server.php b/apps/dav/lib/server.php
index e666855644..73e24c9a29 100644
--- a/apps/dav/lib/server.php
+++ b/apps/dav/lib/server.php
@@ -132,8 +132,15 @@ class Server {
 			$user = \OC::$server->getUserSession()->getUser();
 			if (!is_null($user)) {
 				$view = \OC\Files\Filesystem::getView();
-				$this->server->addPlugin(new FilesPlugin($this->server->tree, $view, false,
-					!\OC::$server->getConfig()->getSystemValue('debug', false)));
+				$this->server->addPlugin(
+					new FilesPlugin(
+						$this->server->tree,
+						$view,
+						\OC::$server->getConfig(),
+						false,
+						!\OC::$server->getConfig()->getSystemValue('debug', false)
+					)
+				);
 
 				$this->server->addPlugin(
 					new \Sabre\DAV\PropertyStorage\Plugin(
diff --git a/apps/dav/tests/unit/connector/sabre/filesplugin.php b/apps/dav/tests/unit/connector/sabre/filesplugin.php
index 63ee5a53c1..fb5d658b39 100644
--- a/apps/dav/tests/unit/connector/sabre/filesplugin.php
+++ b/apps/dav/tests/unit/connector/sabre/filesplugin.php
@@ -43,6 +43,7 @@ class FilesPlugin extends TestCase {
 	const DOWNLOADURL_PROPERTYNAME = \OCA\DAV\Connector\Sabre\FilesPlugin::DOWNLOADURL_PROPERTYNAME;
 	const OWNER_ID_PROPERTYNAME = \OCA\DAV\Connector\Sabre\FilesPlugin::OWNER_ID_PROPERTYNAME;
 	const OWNER_DISPLAY_NAME_PROPERTYNAME = \OCA\DAV\Connector\Sabre\FilesPlugin::OWNER_DISPLAY_NAME_PROPERTYNAME;
+	const DATA_FINGERPRINT_PROPERTYNAME = \OCA\DAV\Connector\Sabre\FilesPlugin::DATA_FINGERPRINT_PROPERTYNAME;
 
 	/**
 	 * @var \Sabre\DAV\Server | \PHPUnit_Framework_MockObject_MockObject
@@ -64,6 +65,11 @@ class FilesPlugin extends TestCase {
 	 */
 	private $view;
 
+	/**
+	 * @var \OCP\IConfig | \PHPUnit_Framework_MockObject_MockObject
+	 */
+	private $config;
+
 	public function setUp() {
 		parent::setUp();
 		$this->server = $this->getMockBuilder('\Sabre\DAV\Server')
@@ -75,8 +81,16 @@ class FilesPlugin extends TestCase {
 		$this->view = $this->getMockBuilder('\OC\Files\View')
 			->disableOriginalConstructor()
 			->getMock();
+		$this->config = $this->getMock('\OCP\IConfig');
+		$this->config->method('getSystemValue')
+			->with($this->equalTo('data-fingerprint'), $this->equalTo(''))
+			->willReturn('my_fingerprint');
 
-		$this->plugin = new \OCA\DAV\Connector\Sabre\FilesPlugin($this->tree, $this->view);
+		$this->plugin = new \OCA\DAV\Connector\Sabre\FilesPlugin(
+			$this->tree,
+			$this->view,
+			$this->config
+		);
 		$this->plugin->initialize($this->server);
 	}
 
@@ -128,7 +142,8 @@ class FilesPlugin extends TestCase {
 				self::PERMISSIONS_PROPERTYNAME,
 				self::DOWNLOADURL_PROPERTYNAME,
 				self::OWNER_ID_PROPERTYNAME,
-				self::OWNER_DISPLAY_NAME_PROPERTYNAME
+				self::OWNER_DISPLAY_NAME_PROPERTYNAME,
+				self::DATA_FINGERPRINT_PROPERTYNAME,
 			),
 			0
 		);
@@ -166,7 +181,7 @@ class FilesPlugin extends TestCase {
 		$this->assertEquals('http://example.com/', $propFind->get(self::DOWNLOADURL_PROPERTYNAME));
 		$this->assertEquals('foo', $propFind->get(self::OWNER_ID_PROPERTYNAME));
 		$this->assertEquals('M. Foo', $propFind->get(self::OWNER_DISPLAY_NAME_PROPERTYNAME));
-		$this->assertEquals(array(self::SIZE_PROPERTYNAME), $propFind->get404Properties());
+		$this->assertEquals([self::SIZE_PROPERTYNAME, self::DATA_FINGERPRINT_PROPERTYNAME], $propFind->get404Properties());
 	}
 
 	public function testGetPropertiesForFileHome() {
@@ -185,7 +200,8 @@ class FilesPlugin extends TestCase {
 				self::PERMISSIONS_PROPERTYNAME,
 				self::DOWNLOADURL_PROPERTYNAME,
 				self::OWNER_ID_PROPERTYNAME,
-				self::OWNER_DISPLAY_NAME_PROPERTYNAME
+				self::OWNER_DISPLAY_NAME_PROPERTYNAME,
+				self::DATA_FINGERPRINT_PROPERTYNAME,
 			),
 			0
 		);
@@ -217,6 +233,7 @@ class FilesPlugin extends TestCase {
 					'{http://owncloud.org/ns}owner-id',
 					'{http://owncloud.org/ns}owner-display-name'
 				], $propFind->get404Properties());
+		$this->assertEquals('my_fingerprint', $propFind->get(self::DATA_FINGERPRINT_PROPERTYNAME));
 	}
 
 	public function testGetPropertiesStorageNotAvailable() {
@@ -244,7 +261,11 @@ class FilesPlugin extends TestCase {
 	}
 
 	public function testGetPublicPermissions() {
-		$this->plugin = new \OCA\DAV\Connector\Sabre\FilesPlugin($this->tree, $this->view, true);
+		$this->plugin = new \OCA\DAV\Connector\Sabre\FilesPlugin(
+			$this->tree,
+			$this->view,
+			$this->config,
+			true);
 		$this->plugin->initialize($this->server);
 
 		$propFind = new PropFind(
@@ -281,6 +302,7 @@ class FilesPlugin extends TestCase {
 				self::SIZE_PROPERTYNAME,
 				self::PERMISSIONS_PROPERTYNAME,
 				self::DOWNLOADURL_PROPERTYNAME,
+				self::DATA_FINGERPRINT_PROPERTYNAME,
 			),
 			0
 		);
@@ -299,7 +321,30 @@ class FilesPlugin extends TestCase {
 		$this->assertEquals(1025, $propFind->get(self::SIZE_PROPERTYNAME));
 		$this->assertEquals('DWCKMSR', $propFind->get(self::PERMISSIONS_PROPERTYNAME));
 		$this->assertEquals(null, $propFind->get(self::DOWNLOADURL_PROPERTYNAME));
-		$this->assertEquals(array(self::DOWNLOADURL_PROPERTYNAME), $propFind->get404Properties());
+		$this->assertEquals([self::DOWNLOADURL_PROPERTYNAME, self::DATA_FINGERPRINT_PROPERTYNAME], $propFind->get404Properties());
+	}
+
+	public function testGetPropertiesForRootDirectory() {
+		/** @var \OCA\DAV\Connector\Sabre\Directory | \PHPUnit_Framework_MockObject_MockObject $node */
+		$node = $this->getMockBuilder('\OCA\DAV\Connector\Sabre\Directory')
+			->disableOriginalConstructor()
+			->getMock();
+		$node->method('getPath')->willReturn('/');
+
+		$propFind = new PropFind(
+			'/',
+			[
+				self::DATA_FINGERPRINT_PROPERTYNAME,
+			],
+			0
+		);
+
+		$this->plugin->handleGetProperties(
+			$propFind,
+			$node
+		);
+
+		$this->assertEquals('my_fingerprint', $propFind->get(self::DATA_FINGERPRINT_PROPERTYNAME));
 	}
 
 	public function testUpdateProps() {
diff --git a/apps/dav/tests/unit/connector/sabre/filesreportplugin.php b/apps/dav/tests/unit/connector/sabre/filesreportplugin.php
index 87973ef007..ffe1a19ee5 100644
--- a/apps/dav/tests/unit/connector/sabre/filesreportplugin.php
+++ b/apps/dav/tests/unit/connector/sabre/filesreportplugin.php
@@ -336,7 +336,15 @@ class FilesReportPlugin extends \Test\TestCase {
 			->method('getSize')
 			->will($this->returnValue(1024));
 
-		$this->server->addPlugin(new \OCA\DAV\Connector\Sabre\FilesPlugin($this->tree, $this->view));
+		$config = $this->getMock('\OCP\IConfig');
+
+		$this->server->addPlugin(
+			new \OCA\DAV\Connector\Sabre\FilesPlugin(
+				$this->tree,
+				$this->view,
+				$config
+			)
+		);
 		$this->plugin->initialize($this->server);
 		$responses = $this->plugin->prepareResponses($requestedProps, [$node1, $node2]);
 
diff --git a/config/config.sample.php b/config/config.sample.php
index b54bbf6a7b..db662cfd74 100644
--- a/config/config.sample.php
+++ b/config/config.sample.php
@@ -1209,6 +1209,19 @@ $CONFIG = array(
  */
 'debug' => false,
 
+/**
+ * Sets the data-fingerprint of the current data served
+ *
+ * This is a property used by the clients to find out if a backup has been
+ * restored on the server. Once a backup is restored run
+ * ./occ maintenance:data-fingerprint
+ * To set this to a new value.
+ *
+ * Updating/Deleting this value can make connected clients stall until
+ * the user has resolved conflicts.
+ */
+'data-fingerprint' => '',
+
 /**
  * This entry is just here to show a warning in case somebody copied the sample
  * configuration. DO NOT ADD THIS SWITCH TO YOUR CONFIGURATION!
diff --git a/core/Command/Maintenance/DataFingerprint.php b/core/Command/Maintenance/DataFingerprint.php
new file mode 100644
index 0000000000..38f490fd12
--- /dev/null
+++ b/core/Command/Maintenance/DataFingerprint.php
@@ -0,0 +1,53 @@
+<?php
+/**
+ * @author Roeland Jago Douma <rullzer@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OC\Core\Command\Maintenance;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IConfig;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+
+class DataFingerprint extends Command {
+
+	/** @var IConfig */
+	protected $config;
+	/** @var ITimeFactory */
+	protected $timeFactory;
+
+	public function __construct(IConfig $config,
+								ITimeFactory $timeFactory) {
+		$this->config = $config;
+		$this->timeFactory = $timeFactory;
+		parent::__construct();
+	}
+
+	protected function configure() {
+		$this
+			->setName('maintenance:data-fingerprint')
+			->setDescription('update the systems data-fingerprint after a backup is restored');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+		$this->config->setSystemValue('data-fingerprint', md5($this->timeFactory->getTime()));
+	}
+}
diff --git a/core/register_command.php b/core/register_command.php
index 17bd573133..90a54233e6 100644
--- a/core/register_command.php
+++ b/core/register_command.php
@@ -108,6 +108,7 @@ if (\OC::$server->getConfig()->getSystemValue('installed', false)) {
 	);
 	$application->add(new OC\Core\Command\Encryption\ShowKeyStorageRoot($util));
 
+	$application->add(new OC\Core\Command\Maintenance\DataFingerprint(\OC::$server->getConfig(), new \OC\AppFramework\Utility\TimeFactory()));
 	$application->add(new OC\Core\Command\Maintenance\Mimetype\UpdateDB(\OC::$server->getMimeTypeDetector(), \OC::$server->getMimeTypeLoader()));
 	$application->add(new OC\Core\Command\Maintenance\Mimetype\UpdateJS(\OC::$server->getMimeTypeDetector()));
 	$application->add(new OC\Core\Command\Maintenance\Mode(\OC::$server->getConfig()));
diff --git a/tests/core/command/maintenance/datafingerprinttest.php b/tests/core/command/maintenance/datafingerprinttest.php
new file mode 100644
index 0000000000..4d661b5c02
--- /dev/null
+++ b/tests/core/command/maintenance/datafingerprinttest.php
@@ -0,0 +1,64 @@
+<?php
+/**
+ * @author Roeland Jago Douma <rullzer@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace Tests\Core\Command\Maintenance;
+
+use OC\Core\Command\Maintenance\DataFingerprint;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IConfig;
+use Test\TestCase;
+
+class DataFingerprintTest extends TestCase {
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
+	protected $config;
+	/** @var \PHPUnit_Framework_MockObject_MockObject */
+	protected $consoleInput;
+	/** @var \PHPUnit_Framework_MockObject_MockObject */
+	protected $consoleOutput;
+	/** @var ITimeFactory|\PHPUnit_Framework_MockObject_MockObject */
+	protected $timeFactory;
+
+	/** @var \Symfony\Component\Console\Command\Command */
+	protected $command;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$this->config = $this->getMock('OCP\IConfig');
+		$this->timeFactory = $this->getMock('OCP\AppFramework\Utility\ITimeFactory');
+		$this->consoleInput = $this->getMock('Symfony\Component\Console\Input\InputInterface');
+		$this->consoleOutput = $this->getMock('Symfony\Component\Console\Output\OutputInterface');
+
+		/** @var \OCP\IConfig $config */
+		$this->command = new DataFingerprint($this->config, $this->timeFactory);
+	}
+
+	public function testSetFingerPrint() {
+		$this->timeFactory->expects($this->once())
+			->method('getTime')
+			->willReturn(42);
+		$this->config->expects($this->once())
+			->method('setSystemValue')
+			->with('data-fingerprint', md5(42));
+
+		self::invokePrivate($this->command, 'execute', [$this->consoleInput, $this->consoleOutput]);
+	}
+}