Over the holiday break one of our servers suffered a disk failure in the main raid set.
The disk was replaced and the raid set repaired. All seemed to be going well,
until SQL Server wouldn’t start. Checking the latest ERRORLOG for SQL Server

2005-12-28 10:44:26.17 spid3     Starting up database 'master'.
2005-12-28 10:44:26.18 spid3     Error: 823, Severity: 24, State: 6.
2005-12-28 10:44:26.18 spid3     Error: 5173, Severity: 16, State: 1.
2005-12-28 10:44:26.18 spid3     Error: 5180, Severity: 22, State: 1.

and nothing more. Looking up the error numbers in BOL shows:

Error 823 – Microsoft� SQL Server� encountered an I/O error on a read or write request made to a device. This error usually indicates disk problems. However, additional kernel messages in the error log, recorded before error 823, should indicate which device is involved.

Error 5173 – Cannot associate files with different databases.

Error 5180 – Could not open FCB for invalid file ID %d in database ‘%.*ls’.

With a master database this corrupted, SQL Server will not start. So the first
task is to rebuild the master database, and then restore the orginal from a
backup before the disk corruption occured. Once SQL Server is working again
I’ll check all the other databases for corruption.

Continue on to [story:sql2000-rebuild-master-database].