diff --git a/apps/files/lib/BackgroundJob/DeleteOrphanedItems.php b/apps/files/lib/BackgroundJob/DeleteOrphanedItems.php
index 32fb569a3d462..b1a795b775cc9 100644
--- a/apps/files/lib/BackgroundJob/DeleteOrphanedItems.php
+++ b/apps/files/lib/BackgroundJob/DeleteOrphanedItems.php
@@ -52,34 +52,86 @@ public function run($argument) {
 	 * @param string $typeCol
 	 * @return int Number of deleted entries
 	 */
-	protected function cleanUp($table, $idCol, $typeCol) {
+	protected function cleanUp(string $table, string $idCol, string $typeCol): int {
 		$deletedEntries = 0;
 
-		$query = $this->connection->getQueryBuilder();
-		$query->select('t1.' . $idCol)
-			->from($table, 't1')
-			->where($query->expr()->eq($typeCol, $query->expr()->literal('files')))
-			->leftJoin('t1', 'filecache', 't2', $query->expr()->eq($query->expr()->castColumn('t1.' . $idCol, IQueryBuilder::PARAM_INT), 't2.fileid'))
-			->andWhere($query->expr()->isNull('t2.fileid'))
-			->groupBy('t1.' . $idCol)
-			->setMaxResults(self::CHUNK_SIZE);
-
 		$deleteQuery = $this->connection->getQueryBuilder();
 		$deleteQuery->delete($table)
-			->where($deleteQuery->expr()->in($idCol, $deleteQuery->createParameter('objectid')));
+			->where($deleteQuery->expr()->eq($idCol, $deleteQuery->createParameter('objectid')));
+
+		if ($this->connection->getShardDefinition('filecache')) {
+			$sourceIdChunks = $this->getItemIds($table, $idCol, $typeCol, 1000);
+			foreach ($sourceIdChunks as $sourceIdChunk) {
+				$deletedSources = $this->findMissingSources($sourceIdChunk);
+				$deleteQuery->setParameter('objectid', $deletedSources, IQueryBuilder::PARAM_INT_ARRAY);
+				$deletedEntries += $deleteQuery->executeStatement();
+			}
+		} else {
+			$query = $this->connection->getQueryBuilder();
+			$query->select('t1.' . $idCol)
+				->from($table, 't1')
+				->where($query->expr()->eq($typeCol, $query->expr()->literal('files')))
+				->leftJoin('t1', 'filecache', 't2', $query->expr()->eq($query->expr()->castColumn('t1.' . $idCol, IQueryBuilder::PARAM_INT), 't2.fileid'))
+				->andWhere($query->expr()->isNull('t2.fileid'))
+				->groupBy('t1.' . $idCol)
+				->setMaxResults(self::CHUNK_SIZE);
+
+			$deleteQuery = $this->connection->getQueryBuilder();
+			$deleteQuery->delete($table)
+				->where($deleteQuery->expr()->in($idCol, $deleteQuery->createParameter('objectid')));
 
-		$deletedInLastChunk = self::CHUNK_SIZE;
-		while ($deletedInLastChunk === self::CHUNK_SIZE) {
-			$chunk = $query->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
-			$deletedInLastChunk = count($chunk);
+			$deletedInLastChunk = self::CHUNK_SIZE;
+			while ($deletedInLastChunk === self::CHUNK_SIZE) {
+				$chunk = $query->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+				$deletedInLastChunk = count($chunk);
 
-			$deleteQuery->setParameter('objectid', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
-			$deletedEntries += $deleteQuery->executeStatement();
+				$deleteQuery->setParameter('objectid', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
+				$deletedEntries += $deleteQuery->executeStatement();
+			}
 		}
 
 		return $deletedEntries;
 	}
 
+	/**
+	 * @param string $table
+	 * @param string $idCol
+	 * @param string $typeCol
+	 * @param int $chunkSize
+	 * @return \Iterator<int[]>
+	 * @throws \OCP\DB\Exception
+	 */
+	private function getItemIds(string $table, string $idCol, string $typeCol, int $chunkSize): \Iterator {
+		$query = $this->connection->getQueryBuilder();
+		$query->select($idCol)
+			->from($table)
+			->where($query->expr()->eq($typeCol, $query->expr()->literal('files')))
+			->groupBy($idCol)
+			->andWhere($query->expr()->gt($idCol, $query->createParameter('min_id')))
+			->setMaxResults($chunkSize);
+
+		$minId = 0;
+		while (true) {
+			$query->setParameter('min_id', $minId);
+			$rows = $query->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+			if (count($rows) > 0) {
+				$minId = $rows[count($rows) - 1];
+				yield $rows;
+			} else {
+				break;
+			}
+		}
+	}
+
+	private function findMissingSources(array $ids): array {
+		$qb = $this->connection->getQueryBuilder();
+		$qb->select('fileid')
+			->from('filecache')
+			->where($qb->expr()->in('fileid', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)));
+		$found = $qb->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+		return array_diff($ids, $found);
+	}
+
 	/**
 	 * Deleting orphaned system tag mappings
 	 *
diff --git a/apps/files/lib/Command/DeleteOrphanedFiles.php b/apps/files/lib/Command/DeleteOrphanedFiles.php
index b7101c072586f..047e26f11eca7 100644
--- a/apps/files/lib/Command/DeleteOrphanedFiles.php
+++ b/apps/files/lib/Command/DeleteOrphanedFiles.php
@@ -35,34 +35,29 @@ protected function configure(): void {
 
 	public function execute(InputInterface $input, OutputInterface $output): int {
 		$deletedEntries = 0;
+		$fileIdsByStorage = [];
 
-		$query = $this->connection->getQueryBuilder();
-		$query->select('fc.fileid')
-			->from('filecache', 'fc')
-			->where($query->expr()->isNull('s.numeric_id'))
-			->leftJoin('fc', 'storages', 's', $query->expr()->eq('fc.storage', 's.numeric_id'))
-			->setMaxResults(self::CHUNK_SIZE);
+		$deletedStorages = array_diff($this->getReferencedStorages(), $this->getExistingStorages());
+
+		$deleteExtended = !$input->getOption('skip-filecache-extended');
+		if ($deleteExtended) {
+			$fileIdsByStorage = $this->getFileIdsForStorages($deletedStorages);
+		}
 
 		$deleteQuery = $this->connection->getQueryBuilder();
 		$deleteQuery->delete('filecache')
-			->where($deleteQuery->expr()->eq('fileid', $deleteQuery->createParameter('objectid')));
+			->where($deleteQuery->expr()->in('storage', $deleteQuery->createParameter('storage_ids')));
 
-		$deletedInLastChunk = self::CHUNK_SIZE;
-		while ($deletedInLastChunk === self::CHUNK_SIZE) {
-			$deletedInLastChunk = 0;
-			$result = $query->execute();
-			while ($row = $result->fetch()) {
-				$deletedInLastChunk++;
-				$deletedEntries += $deleteQuery->setParameter('objectid', (int) $row['fileid'])
-					->execute();
-			}
-			$result->closeCursor();
+		$deletedStorageChunks = array_chunk($deletedStorages, self::CHUNK_SIZE);
+		foreach ($deletedStorageChunks as $deletedStorageChunk) {
+			$deleteQuery->setParameter('storage_ids', $deletedStorageChunk, IQueryBuilder::PARAM_INT_ARRAY);
+			$deletedEntries += $deleteQuery->executeStatement();
 		}
 
 		$output->writeln("$deletedEntries orphaned file cache entries deleted");
 
-		if (!$input->getOption('skip-filecache-extended')) {
-			$deletedFileCacheExtended = $this->cleanupOrphanedFileCacheExtended();
+		if ($deleteExtended) {
+			$deletedFileCacheExtended = $this->cleanupOrphanedFileCacheExtended($fileIdsByStorage);
 			$output->writeln("$deletedFileCacheExtended orphaned file cache extended entries deleted");
 		}
 
@@ -72,28 +67,63 @@ public function execute(InputInterface $input, OutputInterface $output): int {
 		return self::SUCCESS;
 	}
 
-	private function cleanupOrphanedFileCacheExtended(): int {
-		$deletedEntries = 0;
-
+	private function getReferencedStorages(): array {
 		$query = $this->connection->getQueryBuilder();
-		$query->select('fce.fileid')
-			->from('filecache_extended', 'fce')
-			->leftJoin('fce', 'filecache', 'fc', $query->expr()->eq('fce.fileid', 'fc.fileid'))
-			->where($query->expr()->isNull('fc.fileid'))
-			->setMaxResults(self::CHUNK_SIZE);
+		$query->select('storage')
+			->from('filecache')
+			->groupBy('storage')
+			->runAcrossAllShards();
+		return $query->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+	}
 
-		$deleteQuery = $this->connection->getQueryBuilder();
-		$deleteQuery->delete('filecache_extended')
-			->where($deleteQuery->expr()->in('fileid', $deleteQuery->createParameter('idsToDelete')));
+	private function getExistingStorages(): array {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('numeric_id')
+			->from('storages')
+			->groupBy('numeric_id');
+		return $query->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+	}
 
-		$result = $query->executeQuery();
-		while ($result->rowCount() > 0) {
-			$idsToDelete = $result->fetchAll(\PDO::FETCH_COLUMN);
+	/**
+	 * @param int[] $storageIds
+	 * @return array<int, int[]>
+	 */
+	private function getFileIdsForStorages(array $storageIds): array {
+		$query = $this->connection->getQueryBuilder();
+		$query->select('storage', 'fileid')
+			->from('filecache')
+			->where($query->expr()->in('storage', $query->createParameter('storage_ids')));
+
+		$result = [];
+		$storageIdChunks = array_chunk($storageIds, self::CHUNK_SIZE);
+		foreach ($storageIdChunks as $storageIdChunk) {
+			$query->setParameter('storage_ids', $storageIdChunk, IQueryBuilder::PARAM_INT_ARRAY);
+			$chunk = $query->executeQuery()->fetchAll();
+			foreach ($chunk as $row) {
+				$result[$row['storage']][] = $row['fileid'];
+			}
+		}
+		return $result;
+	}
 
-			$deleteQuery->setParameter('idsToDelete', $idsToDelete, IQueryBuilder::PARAM_INT_ARRAY);
-			$deletedEntries += $deleteQuery->executeStatement();
+	/**
+	 * @param array<int, int[]> $fileIdsByStorage
+	 * @return int
+	 */
+	private function cleanupOrphanedFileCacheExtended(array $fileIdsByStorage): int {
+		$deletedEntries = 0;
 
-			$result = $query->executeQuery();
+		$deleteQuery = $this->connection->getQueryBuilder();
+		$deleteQuery->delete('filecache_extended')
+			->where($deleteQuery->expr()->in('fileid', $deleteQuery->createParameter('file_ids')));
+
+		foreach ($fileIdsByStorage as $storageId => $fileIds) {
+			$deleteQuery->hintShardKey('storage', $storageId, true);
+			$fileChunks = array_chunk($fileIds, self::CHUNK_SIZE);
+			foreach ($fileChunks as $fileChunk) {
+				$deleteQuery->setParameter('file_ids', $fileChunk, IQueryBuilder::PARAM_INT_ARRAY);
+				$deletedEntries += $deleteQuery->executeStatement();
+			}
 		}
 
 		return $deletedEntries;
diff --git a/apps/files/tests/Command/DeleteOrphanedFilesTest.php b/apps/files/tests/Command/DeleteOrphanedFilesTest.php
index e52f9e1e1305a..ed9a1866d2616 100644
--- a/apps/files/tests/Command/DeleteOrphanedFilesTest.php
+++ b/apps/files/tests/Command/DeleteOrphanedFilesTest.php
@@ -64,13 +64,19 @@ protected function tearDown(): void {
 	}
 
 	protected function getFile($fileId) {
-		$stmt = $this->connection->executeQuery('SELECT * FROM `*PREFIX*filecache` WHERE `fileid` = ?', [$fileId]);
-		return $stmt->fetchAll();
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('filecache')
+			->where($query->expr()->eq('fileid', $query->createNamedParameter($fileId)));
+		return $query->executeQuery()->fetchAll();
 	}
 
 	protected function getMounts($storageId) {
-		$stmt = $this->connection->executeQuery('SELECT * FROM `*PREFIX*mounts` WHERE `storage_id` = ?', [$storageId]);
-		return $stmt->fetchAll();
+		$query = $this->connection->getQueryBuilder();
+		$query->select('*')
+			->from('mounts')
+			->where($query->expr()->eq('storage_id', $query->createNamedParameter($storageId)));
+		return $query->executeQuery()->fetchAll();
 	}
 
 	/**
diff --git a/apps/files_sharing/lib/DeleteOrphanedSharesJob.php b/apps/files_sharing/lib/DeleteOrphanedSharesJob.php
index 9a052b3d126bc..bcbdbaba53165 100644
--- a/apps/files_sharing/lib/DeleteOrphanedSharesJob.php
+++ b/apps/files_sharing/lib/DeleteOrphanedSharesJob.php
@@ -55,6 +55,11 @@ public function __construct(
 	 * @param array $argument unused argument
 	 */
 	public function run($argument) {
+		if ($this->db->getShardDefinition('filecache')) {
+			$this->shardingCleanup();
+			return;
+		}
+
 		$qbSelect = $this->db->getQueryBuilder();
 		$qbSelect->select('id')
 			->from('share', 's')
@@ -96,4 +101,40 @@ public function run($argument) {
 			}, $this->db);
 		} while ($deleted >= self::CHUNK_SIZE && $this->time->getTime() <= $cutOff);
 	}
+
+	private function shardingCleanup(): void {
+		$qb = $this->db->getQueryBuilder();
+		$qb->selectDistinct('file_source')
+			->from('share', 's');
+		$sourceFiles = $qb->executeQuery()->fetchAll(PDO::FETCH_COLUMN);
+
+		$deleteQb = $this->db->getQueryBuilder();
+		$deleteQb->delete('share')
+			->where(
+				$deleteQb->expr()->in('file_source', $deleteQb->createParameter('ids'), IQueryBuilder::PARAM_INT_ARRAY)
+			);
+
+		$chunks = array_chunk($sourceFiles, self::CHUNK_SIZE);
+		foreach ($chunks as $chunk) {
+			$deletedFiles = $this->findMissingSources($chunk);
+			$this->atomic(function () use ($deletedFiles, $deleteQb) {
+				$deleteQb->setParameter('ids', $deletedFiles, IQueryBuilder::PARAM_INT_ARRAY);
+				$deleted = $deleteQb->executeStatement();
+				$this->logger->debug("{deleted} orphaned share(s) deleted", [
+					'app' => 'DeleteOrphanedSharesJob',
+					'deleted' => $deleted,
+				]);
+				return $deleted;
+			}, $this->db);
+		}
+	}
+
+	private function findMissingSources(array $ids): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('fileid')
+			->from('filecache')
+			->where($qb->expr()->in('fileid', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)));
+		$found = $qb->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+		return array_diff($ids, $found);
+	}
 }
diff --git a/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php b/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php
index 8ed88198c19fc..c40cadfbdb5f6 100644
--- a/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php
@@ -289,8 +289,8 @@ public function executeStatement(?IDBConnection $connection = null): int {
 		return $this->builder->executeStatement($connection);
 	}
 
-	public function hintShardKey(string $column, mixed $value) {
-		$this->builder->hintShardKey($column, $value);
+	public function hintShardKey(string $column, mixed $value, bool $overwrite = false) {
+		$this->builder->hintShardKey($column, $value, $overwrite);
 		return $this;
 	}
 
diff --git a/lib/private/DB/QueryBuilder/QueryBuilder.php b/lib/private/DB/QueryBuilder/QueryBuilder.php
index c8055259f50c4..af89db7e45624 100644
--- a/lib/private/DB/QueryBuilder/QueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/QueryBuilder.php
@@ -1366,7 +1366,7 @@ public function quoteAlias($alias) {
 		return $this->helper->quoteColumnName($alias);
 	}
 
-	public function hintShardKey(string $column, mixed $value) {
+	public function hintShardKey(string $column, mixed $value, bool $overwrite = false) {
 		return $this;
 	}
 
diff --git a/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php b/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php
index 6496453a1a609..650e414096e65 100644
--- a/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php
@@ -296,7 +296,11 @@ private function registerOrder(string $column, string $order): void {
 		];
 	}
 
-	public function hintShardKey(string $column, mixed $value) {
+	public function hintShardKey(string $column, mixed $value, bool $overwrite = false) {
+		if ($overwrite) {
+			$this->primaryKeys = [];
+			$this->shardKeys = [];
+		}
 		if ($this->shardDefinition?->isKey($column)) {
 			$this->primaryKeys[] = $value;
 		}
diff --git a/lib/private/Preview/BackgroundCleanupJob.php b/lib/private/Preview/BackgroundCleanupJob.php
index deadcd007b1af..acf7bf22f5259 100644
--- a/lib/private/Preview/BackgroundCleanupJob.php
+++ b/lib/private/Preview/BackgroundCleanupJob.php
@@ -16,6 +16,7 @@
 use OCP\Files\NotFoundException;
 use OCP\Files\NotPermittedException;
 use OCP\IDBConnection;
+use function Symfony\Component\Translation\t;
 
 class BackgroundCleanupJob extends TimedJob {
 	/** @var IDBConnection */
@@ -64,6 +65,11 @@ private function getDeletedFiles(): \Iterator {
 	}
 
 	private function getOldPreviewLocations(): \Iterator {
+		if ($this->connection->getShardDefinition('filecache')) {
+			// sharding is new enough that we don't need to support this
+			return;
+		}
+
 		$qb = $this->connection->getQueryBuilder();
 		$qb->select('a.name')
 			->from('filecache', 'a')
@@ -106,6 +112,15 @@ private function getNewPreviewLocations(): \Iterator {
 			return [];
 		}
 
+		if ($this->connection->getShardDefinition('filecache')) {
+			$chunks = $this->getAllPreviewIds($data['path'], 1000);
+			foreach ($chunks as $chunk) {
+				yield from $this->findMissingSources($chunk);
+			}
+
+			return;
+		}
+
 		/*
 		 * This lovely like is the result of the way the new previews are stored
 		 * We take the md5 of the name (fileid) and split the first 7 chars. That way
@@ -155,4 +170,46 @@ private function getNewPreviewLocations(): \Iterator {
 
 		$cursor->closeCursor();
 	}
+
+	private function getAllPreviewIds(string $previewRoot, int $chunkSize): \Iterator {
+		// See `getNewPreviewLocations` for some more info about the logic here
+		$like = $this->connection->escapeLikeParameter($previewRoot). '/_/_/_/_/_/_/_/%';
+
+		$qb = $this->connection->getQueryBuilder();
+		$qb->select('name', 'fileid')
+			->from('filecache')
+			->where(
+				$qb->expr()->andX(
+					$qb->expr()->eq('storage', $qb->createNamedParameter($this->previewFolder->getStorageId())),
+					$qb->expr()->like('path', $qb->createNamedParameter($like)),
+					$qb->expr()->eq('mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('httpd/unix-directory'))),
+					$qb->expr()->gt('fileid', $qb->createParameter('min_id')),
+				)
+			)
+			->orderBy('fileid', 'ASC')
+			->setMaxResults($chunkSize);
+
+		$minId = 0;
+		while (true) {
+			$qb->setParameter('min_id', $minId);
+			$rows = $qb->executeQuery()->fetchAll();
+			if (count($rows) > 0) {
+				$minId = $rows[count($rows) - 1]['fileid'];
+				yield array_map(function ($row) {
+					return (int)$row['name'];
+				}, $rows);
+			} else {
+				break;
+			}
+		}
+	}
+
+	private function findMissingSources(array $ids): array {
+		$qb = $this->connection->getQueryBuilder();
+		$qb->select('fileid')
+			->from('filecache')
+			->where($qb->expr()->in('fileid', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)));
+		$found = $qb->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+		return array_diff($ids, $found);
+	}
 }
diff --git a/lib/private/Repair/CleanTags.php b/lib/private/Repair/CleanTags.php
index f2fc8156f29de..b7960a1def1b6 100644
--- a/lib/private/Repair/CleanTags.php
+++ b/lib/private/Repair/CleanTags.php
@@ -107,7 +107,7 @@ protected function deleteOrphanFileEntries(IOutput $output) {
 			$output,
 			'%d tags for delete files have been removed.',
 			'vcategory_to_object', 'objid',
-			'filecache', 'fileid', 'path_hash'
+			'filecache', 'fileid', 'fileid'
 		);
 	}
 
@@ -169,16 +169,17 @@ protected function deleteOrphanEntries(IOutput $output, $repairInfo, $deleteTabl
 			$orphanItems[] = (int) $row[$deleteId];
 		}
 
+		$deleteQuery = $this->connection->getQueryBuilder();
+		$deleteQuery->delete($deleteTable)
+			->where(
+				$deleteQuery->expr()->eq('type', $deleteQuery->expr()->literal('files'))
+			)
+			->andWhere($deleteQuery->expr()->in($deleteId, $deleteQuery->createParameter('ids')));
 		if (!empty($orphanItems)) {
 			$orphanItemsBatch = array_chunk($orphanItems, 200);
 			foreach ($orphanItemsBatch as $items) {
-				$qb->delete($deleteTable)
-					->where(
-						$qb->expr()->eq('type', $qb->expr()->literal('files'))
-					)
-					->andWhere($qb->expr()->in($deleteId, $qb->createParameter('ids')));
-				$qb->setParameter('ids', $items, IQueryBuilder::PARAM_INT_ARRAY);
-				$qb->execute();
+				$deleteQuery->setParameter('ids', $items, IQueryBuilder::PARAM_INT_ARRAY);
+				$deleteQuery->executeStatement();
 			}
 		}
 
diff --git a/lib/public/DB/QueryBuilder/IQueryBuilder.php b/lib/public/DB/QueryBuilder/IQueryBuilder.php
index 048de26c22a1e..b673c5ef6ec77 100644
--- a/lib/public/DB/QueryBuilder/IQueryBuilder.php
+++ b/lib/public/DB/QueryBuilder/IQueryBuilder.php
@@ -1036,7 +1036,7 @@ public function getColumnName($column, $tableAlias = '');
 	 * @return $this
 	 * @since 30.0.0
 	 */
-	public function hintShardKey(string $column, mixed $value);
+	public function hintShardKey(string $column, mixed $value, bool $overwrite = false);
 
 	/**
 	 * Set the query to run across all shards if sharding is enabled.
diff --git a/tests/lib/Preview/BackgroundCleanupJobTest.php b/tests/lib/Preview/BackgroundCleanupJobTest.php
index c07ec42b36b34..ccd5dba69cf05 100644
--- a/tests/lib/Preview/BackgroundCleanupJobTest.php
+++ b/tests/lib/Preview/BackgroundCleanupJobTest.php
@@ -146,6 +146,10 @@ public function testCleanupSystemCron() {
 	}
 
 	public function testCleanupAjax() {
+		if ($this->connection->getShardDefinition('filecache')) {
+			$this->markTestSkipped("ajax cron is not supported for sharded setups");
+			return;
+		}
 		$files = $this->setup11Previews();
 		$fileIds = array_map(function (File $f) {
 			return $f->getId();
@@ -174,6 +178,10 @@ public function testCleanupAjax() {
 	}
 
 	public function testOldPreviews() {
+		if ($this->connection->getShardDefinition('filecache')) {
+			$this->markTestSkipped("old previews are not supported for sharded setups");
+			return;
+		}
 		$appdata = \OC::$server->getAppDataDir('preview');
 
 		$f1 = $appdata->newFolder('123456781');
diff --git a/tests/lib/Repair/CleanTagsTest.php b/tests/lib/Repair/CleanTagsTest.php
index 5e7b82d219889..11430cc121550 100644
--- a/tests/lib/Repair/CleanTagsTest.php
+++ b/tests/lib/Repair/CleanTagsTest.php
@@ -142,7 +142,7 @@ protected function addTagCategory($category, $type, $user = 'TestRepairCleanTags
 			])
 			->execute();
 
-		return (int) $this->getLastInsertID('vcategory', 'id');
+		return $qb->getLastInsertId();
 	}
 
 	/**
@@ -191,16 +191,7 @@ protected function getFileID() {
 			])
 			->execute();
 
-		$this->createdFile = (int) $this->getLastInsertID('filecache', 'fileid');
+		$this->createdFile = $qb->getLastInsertId();
 		return $this->createdFile;
 	}
-
-	/**
-	 * @param $tableName
-	 * @param $idName
-	 * @return int
-	 */
-	protected function getLastInsertID($tableName, $idName) {
-		return $this->connection->lastInsertId("*PREFIX*$tableName");
-	}
 }