ORA-01578 errors

Hi all,

Environment is:

IBM H80 64-bit enterprise server
AIX 5.2
Oracle Enterprise Edition 9.2.0.6 64-bit

A couple of days ago we started seeing a few overnight jobs fail with error ORA-01578 - block corruption. However, checking the indicated data file with dbverify has usually proved negative - i.e. no reported problem. Also, I identified the object associated with the corrupted block - a 10 million row-table - and ran an ANALYZE TABLE VALIDATE STRUCTURE CASCADE command against it which again reported no problem. A full export of the table likewise indicated no problem. The 1578 error then went away but re-appeared in a different file/block.

The day before these errors began to appear I had been moving data between physical disks using AIX's migratepv command. I therefore reasoned that maybe one of the disks I had migrated data to was intermittently causing read errors. The logical volumes concerned are software mirrored (i.e. two LV copies). However, I ran AIX's certify on both disks which contained the data file which apparently had a corrupt block and they checked out OK.

Anyone any thoughts or opinions to add to this? I'm a bit puzzled as to what exactly is going on here.

The database concerned is a production one and running in ARCHIVELOG mode of course so at the worst I can restore to the day prior to running the migratepv commands and recover the database, but I'm loath to do that in case it is a media failure causing the problem as it would achieve nothing bar losing a few hours of time!

Many thanks,

Tim Kearsley
Database Manager HBS Milton Keynes Received on Thu May 11 2006 - 05:55:53 CDT