Re: a question about data corruption

"Jacek Rembisz" <jacek(dot)rembisz(at)gmail(dot)com> writes:
> Postgresql started to log "could not access status of transaction"
> messages. Since the transaction IDs were far away from what
> server was using I took a look at data files i pgsql/base/ and I found
> a total garbage there.

> In five tables (of about 100) I have found a one to four blocks of random data.
> In two places it was data from other table instead of random data.
> All these blocks have sizes which are multiplications of 512 (for
> example 1, 9, 26) and
> starts at offsets which are also a multiplication of 512.

Substituting sector-size blocks of one file for another could easily
be a filesystem (kernel) bug ...

> The system is linux 2.4.31 filesystem XFS on RAID5

... and XFS on such an old kernel version doesn't seem like a very
good bet for stability.

> My question is: Is there any known bug in postgresql 8.0.3 that
> could lead to such a data corruption or is it rather a hardware problem?

No, nothing like that has ever been reported in any released PG
version. If the substituted blocks were from non-Postgres files
then I think you could write off the idea of a PG bug entirely.
It could still be a software issue though.

regards, tom lane