Hi,

DB2 8.2 on windows 2000. We had a strange issue with our database - it failed during onlinebackup with error
SQL0980C A disk error occurred. Subsequent SQL statements cannot be processed. SQLSTATE=58005

We restored the database from backup and still got the same error. Finaly we have detected the error is due missing file in Syscatspace tablespace ( file SQL00001.DAT).

We are concerned with the fact that our online backup did not error because of the corrupt catalog tablespace and also that the restore from the backup did not report any error about the missing file in Tablespace. We also ran db2ckbkp against the backup image that had corrupt syscat contents. Strange db2chkbkp said backup image is perfect! Have anyone else experienced these kind of problems before? How do we avoid this issue of successfull online backups even with the corrupt catalog?


Thanks in advance

It is not clear what is worrying you; backup failed because a file was not available. If you had checked your diaglog you may have found it there; db2's error reporting leaves a lot to be desired. db2ckbkup , depending on the options, just checks for some formats on the header block etc. ; it cannot guarantee internal consistency.

The worry is that db2diag did not report any error about corrupt catalog file. In addition the online backups did not report any error about corrupt catalog. When we restored the database from the backup image it restored with out ant errors. If we try to connect to the restored db we will get

SQL0980C A disk error occurred. Subsequent SQL statements cannot be processed. SQLSTATE=58005.

The situation can be easily simulated on a trial test database..

Create a test db
Activate the test database.
Simulate a catalog corruption by renaming SQL00001.DAT in Syscatspace.

connect to test db - it will connect with the corrupt catalog - could be because DB2 already read catalog data into memeory

take on line back up of test db - it will work ok with no errors!

deactivate test db and the drop test db

restore test db from backup - the restore also will not report an error

now try to connect to test db u will get error..
SQL0980C A disk error occurred. Subsequent SQL statements cannot be processed. SQLSTATE=58005

So the worry is how to be sure that the online backup of our prod db is reliable given this kind of behaviour.

Regards

Harikumar