Re: Fatal error

Jean-Denis Girard <jd-girard@esoft.pf> writes:
> Last tuesday I upgraded a production DB from 7.1 to 7.2.

7.2?  I'd hope you went to 7.2.2, or at least 7.2.1.

> FATAL 2:  open of /var/lib/pgsql/data/pg_clog/0323 failed: No such file 
> or directory

This message implies a bad xmin or xmax field in a stored tuple.  We've
seen a number of reports of similar failures, but so far the evidence
has pointed to hardware failures rather than a software problem ---
corrupted data on disk would usually trigger this kind of failure before
anything else, so the particular error message doesn't seem very
significant.

> Don't know what to do and any help will be welcome. I can also provide 
> more specific information if needed.

You should probably first try some hardware diagnostics like "memtest86"
and "badblocks".  

I don't want to sound like I'm dismissing the possibility that it's a
Postgres bug.  It could be ... but without more evidence there's not 
much I can do to poke into it.
        regards, tom lane