Monday, October 25, 2010

Sql Recovery When Filestream Corruption Damaged Sql Server Database

When you try to restore the Microsoft SQL Server 2008 database (MDF file) from the sequence of transaction log backups, MS SQL Server 2008 database gets damaged. However, the original database, from which you took backup of the transaction log has not damaged. In these situations, the restore operation could not take place and thus your database become inaccessible and critical data loss situations occur. At this point, to gain access of your mission critical data, you are required to carry out SQL Recovery using appropriate solutions.

When the above problem of database corruption occurs, you might encounter the following event in the Application Event log of Microsoft SQL Server:

"Filestream corruption - missing files, error 7904.

The corruption is detected on a database that was restored from a sequence of backup logs. The original database does not seem to be corrupted.

7904 16 2 Table error: The filestream file for "FileID" was not found."

In above scenario, the data loss situations occur. In such cases, you get your valuable data back, you need to find out the cause of this problem and go for SQL Repair by sorting out this issue.

Grounds of the issue

This behavior of Microsoft SQL Server occurs due to filestream corruption. When it happens, the SQL Server database gets damaged as stated in above error message, and the database become inaccessible.

The Filestream is a critical SQL Server database component that integrates SQL Server Database Engine with NTFS file system by storing the varbinary(max) BLOB (Binary Large Object) data as the files on file system. Win32 file system interfaces offer streaming access to data. It uses NT system cache for data caching.

In all these cases, you encounter database corruption and need to go for SQL Recovery by repairing and restoring the database.

Recovery is best possible with the help of powerful and advanced third party applications, known as SQL Repair tool. They perform extensive scan of damaged database to extract all of the database objects such as tables, reports, forms, triggers and stored procedures.

These tools come equipped with interactive and simple graphical user interface and thus do not require sound and prior technical skills to carry out recovery process. With read-only behavior, they do not alter original contents of the database.