SQL Error 7904: File Stream Corruption In SQL Server Database

Filestream corruption in SQL Server database occurs when database gets corrupted while restoring primary database (MDF) files from sequence of transaction log backups. Whereas the original database where the transactions logs are backed up is in a healthy state and is not corrupted. Such instance occurs in SQL Server 2008 version. In such cases, the following errors are registered in MS SQL Server Event Log that states:

Table error 7903: The orphaned file "%.*ls" was found in the FILESTREAM directory ID %.*ls for object ID %d, index ID %d, partition ID %I64d, column ID %d.

Table error 7904: Cannot find the FILESTREAM file "%.*ls" for column ID %d (column directory ID %.*ls) in object ID %d, index ID %d, partition ID %I64d, page ID %S_PGID, slot ID %d.

Root Cause of SQL Error 7903 & 7904

Reason behind the occurrence of this error is SQL Server file stream corruption that leads to corruption of SQL Server database due to which MDF files becomes inaccessible. This is often known as SQL Filestream corruption.

File Stream is a feature in SQL Server for storage and management of unstructured data like images and documents on file systems (NTFS). It may influence the Application Programming Interface (API) of file system but at same time maintains transactional uniformity between structured data and corresponding unstructured data.

Stepwise Occurrence of Filestream Error

When a rushing situation arises in between the skipped files that are suppose to backup via transaction log backup procedure, the SQL server error 7904 occurs. The stepwise occurrence of the situation is mentioned below:

• Files under active transaction are assigned log sequence number in createLSN column.
• The number assigned to file in createLSN column is lesser than log sequence number of lastLSN column.
• When FSLOG entry is not registered in $FSLOG folder on time, backup course for existing transaction log marked the file as "skipped".
• The skipped file is not backed up by afterward transaction log backup procedure. It leads to occurrence of interrupted log sequence.

Recover Database From Filestream Corruption Error

To resolve the issue related to SQL Server filestream corruption, MDF file recovery software can be approached for effective recovery of database. The tool performs scan through powerful algorithm on corrupt database files including all the components such as stored procedures, tables, rules, views, triggers, etc. The tool is capable of recovering files that have become inaccessible due to SQL error 7904. It proficiently recovers healthy data from inaccessible MDF files and restores it in either SQL Server Database or SQL Server compatible scripts.