topic Re: Oracle data block corruption - disk array va7400 in Operating System - HP-UX

Oracle data block corruption - disk array va7400

Michele (Mike) Alberton — Thu, 18 Sep 2003 11:18:33 GMT

Hi,

we're experiencing a very strange behavior on our rp7400 (HP-UX 11.00), running Oracle 8.1.6 on a va7400/ds2405 array system.

We encountered a series of errors (ORA-01578 data block corruption).

We could not find any evidence of disk corruption or array corruption so that we're in the middle of nowhere, no hints on where to look for more.

Is there any way to correlate Oracle blocknum/file coordinates to physical entities on the disk array, and eventually run some low level diagnostics on each single drive to check for sanity ?

Thanks !

Mike

Re: Oracle data block corruption - disk array va7400

Alexander M. Ermes — Thu, 18 Sep 2003 12:16:13 GMT

Hi there.
Oracle block corruption is not necessarily connected to a broken disk.
Pls check your alert log file for the time this started.
If you copy the file with the corrupted block to a different place, did you think about a restore of the broken file or all DATABASE files and a recover_until_time ?
How about your backups ?
Rgds
Alexander M. Ermes

Re: Oracle data block corruption - disk array va7400

Michele (Mike) Alberton — Thu, 18 Sep 2003 12:25:42 GMT

Hi Alexander,

let me tell you something more about this one;
we recreated entirely the DB after wiping out the former datafiles (we have a fixed number of datafiles, so that all the space gets allocated at DB creation time), and at the end I ran dbv on all the datafiles without finding any Marked Corrupt pages.
At that point we started an import (imp) of the the data dump we had (as far as I understand the exp should only extract consistent data) and only after that we found the data corrupted blocks, on 40/50 % of the datafiles, including rbs, temp, sometimes even system.

We involved HP support but they could not geny any HW issue out of the array logs.

Any help would be greatly appreciated ...

Thanks !

Mike

Re: Oracle data block corruption - disk array va7400

IWANIEC, EDOUARD — Fri, 19 Sep 2003 06:30:59 GMT

Hi,

as Alexander told, it's not neccessarily an array problem. Once I had the same type of block corruption and the reason of it was badly operating memorymodules. In my case the array worked perfectly but the data in db_buffer became corrupt. I could see the parity error messages in the operating system's log.

with regards
Laszlo