diff --git a/apps/dav/lib/Connector/Sabre/File.php b/apps/dav/lib/Connector/Sabre/File.php
index e577510b69..45b31c2e11 100644
--- a/apps/dav/lib/Connector/Sabre/File.php
+++ b/apps/dav/lib/Connector/Sabre/File.php
@@ -156,7 +156,7 @@ class File extends Node implements IFile {
 		try {
 			$target = $partStorage->fopen($internalPartPath, 'wb');
 			if ($target === false) {
-				\OCP\Util::writeLog('webdav', '\OC\Files\Filesystem::fopen() failed', \OCP\Util::ERROR);
+				\OC::$server->getLogger()->error('\OC\Files\Filesystem::fopen() failed', ['app' => 'webdav']);
 				// because we have no clue about the cause we can only throw back a 500/Internal Server Error
 				throw new Exception('Could not write file contents');
 			}
@@ -209,7 +209,7 @@ class File extends Node implements IFile {
 						$fileExists = $storage->file_exists($internalPath);
 					}
 					if (!$run || $renameOkay === false || $fileExists === false) {
-						\OCP\Util::writeLog('webdav', 'renaming part file to final file failed ($run: ' . ( $run ? 'true' : 'false' ) . ', $renameOkay: '  . ( $renameOkay ? 'true' : 'false' ) . ', $fileExists: ' . ( $fileExists ? 'true' : 'false' ) . ')', \OCP\Util::ERROR);
+						\OC::$server->getLogger()->error('renaming part file to final file failed ($run: ' . ( $run ? 'true' : 'false' ) . ', $renameOkay: '  . ( $renameOkay ? 'true' : 'false' ) . ', $fileExists: ' . ( $fileExists ? 'true' : 'false' ) . ')', ['app' => 'webdav']);
 						throw new Exception('Could not rename part file to final file');
 					}
 				} catch (ForbiddenException $ex) {
@@ -474,7 +474,7 @@ class File extends Node implements IFile {
 					$renameOkay = $targetStorage->moveFromStorage($partStorage, $partInternalPath, $targetInternalPath);
 					$fileExists = $targetStorage->file_exists($targetInternalPath);
 					if ($renameOkay === false || $fileExists === false) {
-						\OCP\Util::writeLog('webdav', '\OC\Files\Filesystem::rename() failed', \OCP\Util::ERROR);
+						\OC::$server->getLogger()->error('\OC\Files\Filesystem::rename() failed', ['app' => 'webdav']);
 						// only delete if an error occurred and the target file was already created
 						if ($fileExists) {
 							// set to null to avoid double-deletion when handling exception
diff --git a/apps/federatedfilesharing/lib/Controller/RequestHandlerController.php b/apps/federatedfilesharing/lib/Controller/RequestHandlerController.php
index 90346546a2..4953b7c81a 100644
--- a/apps/federatedfilesharing/lib/Controller/RequestHandlerController.php
+++ b/apps/federatedfilesharing/lib/Controller/RequestHandlerController.php
@@ -140,13 +140,14 @@ class RequestHandlerController extends OCSController {
 			}
 
 			// FIXME this should be a method in the user management instead
-			\OCP\Util::writeLog('files_sharing', 'shareWith before, ' . $shareWith, \OCP\Util::DEBUG);
+			$logger = \OC::$server->getLogger();
+			$logger->debug('shareWith before, ' . $shareWith, ['app' => 'files_sharing']);
 			\OCP\Util::emitHook(
 				'\OCA\Files_Sharing\API\Server2Server',
 				'preLoginNameUsedAsUserName',
 				array('uid' => &$shareWith)
 			);
-			\OCP\Util::writeLog('files_sharing', 'shareWith after, ' . $shareWith, \OCP\Util::DEBUG);
+			$logger->debug('shareWith after, ' . $shareWith, ['app' => 'files_sharing']);
 
 			if (!\OC::$server->getUserManager()->userExists($shareWith)) {
 				throw new OCSException('User does not exists', 400);
diff --git a/apps/files_external/lib/Service/LegacyStoragesService.php b/apps/files_external/lib/Service/LegacyStoragesService.php
index 6588051491..f1bd0b753a 100644
--- a/apps/files_external/lib/Service/LegacyStoragesService.php
+++ b/apps/files_external/lib/Service/LegacyStoragesService.php
@@ -140,11 +140,7 @@ abstract class LegacyStoragesService {
 					$parts = explode('/', ltrim($rootMountPath, '/'), 3);
 					if (count($parts) < 3) {
 						// something went wrong, skip
-						\OCP\Util::writeLog(
-							'files_external',
-							'Could not parse mount point "' . $rootMountPath . '"',
-							\OCP\Util::ERROR
-						);
+						\OC::$server->getLogger()->error('Could not parse mount point "' . $rootMountPath . '"', ['app' => 'files_external']);
 						continue;
 					}
 					$relativeMountPath = rtrim($parts[2], '/');
diff --git a/apps/files_sharing/lib/ShareBackend/File.php b/apps/files_sharing/lib/ShareBackend/File.php
index dc1018f88a..bb28c1a33a 100644
--- a/apps/files_sharing/lib/ShareBackend/File.php
+++ b/apps/files_sharing/lib/ShareBackend/File.php
@@ -229,7 +229,7 @@ class File implements \OCP\Share_Backend_File_Dependent {
 		if (isset($fileOwner)) {
 			$source['fileOwner'] = $fileOwner;
 		} else {
-			\OCP\Util::writeLog('files_sharing', "No owner found for reshare", \OCP\Util::ERROR);
+			\OC::$server->getLogger()->error('No owner found for reshare', ['app' => 'files_sharing']);
 		}
 
 		return $source;
diff --git a/apps/files_sharing/lib/SharedMount.php b/apps/files_sharing/lib/SharedMount.php
index d90673421c..1f5b7eaa13 100644
--- a/apps/files_sharing/lib/SharedMount.php
+++ b/apps/files_sharing/lib/SharedMount.php
@@ -167,9 +167,7 @@ class SharedMount extends MountPoint implements MoveableMount {
 
 		// it is not a file relative to data/user/files
 		if (count($split) < 3 || $split[1] !== 'files') {
-			\OCP\Util::writeLog('file sharing',
-				'Can not strip userid and "files/" from path: ' . $path,
-				\OCP\Util::ERROR);
+			\OC::$server->getLogger()->error('Can not strip userid and "files/" from path: ' . $path, ['app' => 'files_sharing']);
 			throw new \OCA\Files_Sharing\Exceptions\BrokenPath('Path does not start with /user/files', 10);
 		}
 
@@ -198,9 +196,7 @@ class SharedMount extends MountPoint implements MoveableMount {
 			$this->setMountPoint($target);
 			$this->storage->setMountPoint($relTargetPath);
 		} catch (\Exception $e) {
-			\OCP\Util::writeLog('file sharing',
-				'Could not rename mount point for shared folder "' . $this->getMountPoint() . '" to "' . $target . '"',
-				\OCP\Util::ERROR);
+			\OC::$server->getLogger()->logException($e, ['app' => 'files_sharing', 'message' => 'Could not rename mount point for shared folder "' . $this->getMountPoint() . '" to "' . $target . '"']);
 		}
 
 		return $result;
diff --git a/apps/files_trashbin/lib/Trashbin.php b/apps/files_trashbin/lib/Trashbin.php
index 3c32e6446c..bf396d40ab 100644
--- a/apps/files_trashbin/lib/Trashbin.php
+++ b/apps/files_trashbin/lib/Trashbin.php
@@ -195,7 +195,7 @@ class Trashbin {
 			$query = \OC_DB::prepare("INSERT INTO `*PREFIX*files_trash` (`id`,`timestamp`,`location`,`user`) VALUES (?,?,?,?)");
 			$result = $query->execute(array($targetFilename, $timestamp, $targetLocation, $user));
 			if (!$result) {
-				\OCP\Util::writeLog('files_trashbin', 'trash bin database couldn\'t be updated for the files owner', \OCP\Util::ERROR);
+				\OC::$server->getLogger()->error('trash bin database couldn\'t be updated for the files owner', ['app' => 'files_trashbin']);
 			}
 		}
 	}
@@ -257,7 +257,7 @@ class Trashbin {
 			if ($trashStorage->file_exists($trashInternalPath)) {
 				$trashStorage->unlink($trashInternalPath);
 			}
-			\OCP\Util::writeLog('files_trashbin', 'Couldn\'t move ' . $file_path . ' to the trash bin', \OCP\Util::ERROR);
+			\OC::$server->getLogger()->error('Couldn\'t move ' . $file_path . ' to the trash bin', ['app' => 'files_trashbin']);
 		}
 
 		if ($sourceStorage->file_exists($sourceInternalPath)) { // failed to delete the original file, abort
@@ -275,7 +275,7 @@ class Trashbin {
 			$query = \OC_DB::prepare("INSERT INTO `*PREFIX*files_trash` (`id`,`timestamp`,`location`,`user`) VALUES (?,?,?,?)");
 			$result = $query->execute(array($filename, $timestamp, $location, $owner));
 			if (!$result) {
-				\OCP\Util::writeLog('files_trashbin', 'trash bin database couldn\'t be updated', \OCP\Util::ERROR);
+				\OC::$server->getLogger()->error('trash bin database couldn\'t be updated', ['app' => 'files_trashbin']);
 			}
 			\OCP\Util::emitHook('\OCA\Files_Trashbin\Trashbin', 'post_moveToTrash', array('filePath' => Filesystem::normalizePath($file_path),
 				'trashPath' => Filesystem::normalizePath($filename . '.d' . $timestamp)));
@@ -391,7 +391,7 @@ class Trashbin {
 		if ($timestamp) {
 			$location = self::getLocation($user, $filename, $timestamp);
 			if ($location === false) {
-				\OCP\Util::writeLog('files_trashbin', 'trash bin database inconsistent! ($user: ' . $user . ' $filename: ' . $filename . ', $timestamp: ' . $timestamp . ')', \OCP\Util::ERROR);
+				\OC::$server->getLogger()->error('trash bin database inconsistent! ($user: ' . $user . ' $filename: ' . $filename . ', $timestamp: ' . $timestamp . ')', ['app' => 'files_trashbin']);
 			} else {
 				// if location no longer exists, restore file in the root directory
 				if ($location !== '/' &&
@@ -763,7 +763,7 @@ class Trashbin {
 			foreach ($files as $file) {
 				if ($availableSpace < 0 && $expiration->isExpired($file['mtime'], true)) {
 					$tmp = self::delete($file['name'], $user, $file['mtime']);
-					\OCP\Util::writeLog('files_trashbin', 'remove "' . $file['name'] . '" (' . $tmp . 'B) to meet the limit of trash bin size (50% of available quota)', \OCP\Util::INFO);
+					\OC::$server->getLogger()->info('remove "' . $file['name'] . '" (' . $tmp . 'B) to meet the limit of trash bin size (50% of available quota)', ['app' => 'files_trashbin']);
 					$availableSpace += $tmp;
 					$size += $tmp;
 				} else {
diff --git a/apps/files_versions/lib/Storage.php b/apps/files_versions/lib/Storage.php
index f8a6636839..52afdfdaa5 100644
--- a/apps/files_versions/lib/Storage.php
+++ b/apps/files_versions/lib/Storage.php
@@ -658,7 +658,7 @@ class Storage {
 						//distance between two version too small, mark to delete
 						$toDelete[$key] = $version['path'] . '.v' . $version['version'];
 						$size += $version['size'];
-						\OCP\Util::writeLog('files_versions', 'Mark to expire '. $version['path'] .' next version should be ' . $nextVersion . " or smaller. (prevTimestamp: " . $prevTimestamp . "; step: " . $step, \OCP\Util::INFO);
+						\OC::$server->getLogger()->info('Mark to expire '. $version['path'] .' next version should be ' . $nextVersion . " or smaller. (prevTimestamp: " . $prevTimestamp . "; step: " . $step, ['app' => 'files_versions']);
 					} else {
 						$nextVersion = $version['version'] - $step;
 						$prevTimestamp = $version['version'];
@@ -713,7 +713,7 @@ class Storage {
 			// get available disk space for user
 			$user = \OC::$server->getUserManager()->get($uid);
 			if (is_null($user)) {
-				\OCP\Util::writeLog('files_versions', 'Backends provided no user object for ' . $uid, \OCP\Util::ERROR);
+				\OC::$server->getLogger()->error('Backends provided no user object for ' . $uid, ['app' => 'files_versions']);
 				throw new \OC\User\NoUserException('Backends provided no user object for ' . $uid);
 			}
 
@@ -782,12 +782,13 @@ class Storage {
 				$versionsSize = $versionsSize - $sizeOfDeletedVersions;
 			}
 
+			$logger = \OC::$server->getLogger();
 			foreach($toDelete as $key => $path) {
 				\OC_Hook::emit('\OCP\Versions', 'preDelete', array('path' => $path, 'trigger' => self::DELETE_TRIGGER_QUOTA_EXCEEDED));
 				self::deleteVersion($versionsFileview, $path);
 				\OC_Hook::emit('\OCP\Versions', 'delete', array('path' => $path, 'trigger' => self::DELETE_TRIGGER_QUOTA_EXCEEDED));
 				unset($allVersions[$key]); // update array with the versions we keep
-				\OCP\Util::writeLog('files_versions', "Expire: " . $path, \OCP\Util::INFO);
+				$logger->info('Expire: ' . $path, ['app' => 'files_versions']);
 			}
 
 			// Check if enough space is available after versions are rearranged.
@@ -803,7 +804,7 @@ class Storage {
 				\OC_Hook::emit('\OCP\Versions', 'preDelete', array('path' => $version['path'].'.v'.$version['version'], 'trigger' => self::DELETE_TRIGGER_QUOTA_EXCEEDED));
 				self::deleteVersion($versionsFileview, $version['path'] . '.v' . $version['version']);
 				\OC_Hook::emit('\OCP\Versions', 'delete', array('path' => $version['path'].'.v'.$version['version'], 'trigger' => self::DELETE_TRIGGER_QUOTA_EXCEEDED));
-				\OCP\Util::writeLog('files_versions', 'running out of space! Delete oldest version: ' . $version['path'].'.v'.$version['version'] , \OCP\Util::INFO);
+				\OC::$server->getLogger()->info('running out of space! Delete oldest version: ' . $version['path'].'.v'.$version['version'], ['app' => 'files_versions']);
 				$versionsSize -= $version['size'];
 				$availableSpace += $version['size'];
 				next($allVersions);
diff --git a/cron.php b/cron.php
index b566f7ea34..aaa4419c1c 100644
--- a/cron.php
+++ b/cron.php
@@ -41,11 +41,11 @@ try {
 	require_once __DIR__ . '/lib/base.php';
 
 	if (\OCP\Util::needUpgrade()) {
-		\OCP\Util::writeLog('cron', 'Update required, skipping cron', \OCP\Util::DEBUG);
+		\OC::$server->getLogger()->debug('Update required, skipping cron', ['app' => 'cron']);
 		exit;
 	}
 	if (\OC::$server->getSystemConfig()->getValue('maintenance', false)) {
-		\OCP\Util::writeLog('cron', 'We are in maintenance mode, skipping cron', \OCP\Util::DEBUG);
+		\OC::$server->getLogger()->debug('We are in maintenance mode, skipping cron', ['app' => 'cron']);
 		exit;
 	}