Re: Lost rows/data corruption?

On Tue, 2005-02-15 at 04:56, Geoffrey wrote:
> Tom Lane wrote:
> > "Andrew Hall" <temp02(at)bluereef(dot)com(dot)au> writes:
> >
> >> We haven't been able to isolate what causes it but it's unlikely to be
> >> hardware as it happens on quite a few of our customer's boxes.
> >
> >
> > Okay, then not hardware; but it seems like you ought to be in a position
> > to create a test case for other people to poke at. I don't insist on
> > a 100% reproducible case, but something that will show the problem if
> > run for awhile would be a great help.
>
> His original statement prompts a question in my mind. I may be wrong
> here, but when he noted:
>
> 'We also use XFS on linux 2.6 as a file system, so the FS should be
> fairly tolerant to power-outages.'
>
> Is Andrew indicating here that there might be some issues with power
> loss on some of these boxes? If so, is it reasonable to assume that the
> filesystem is able to maintain the database integrity in such a power
> loss? I understand that XFS is quite a robust file system, but I can't
> see relying on such robustness for database integrity (or any file
> integrity for that matter). UPS's might be a better solution.

If I were him I'd try running my database on a different file system to
see if his version of XFS might be causing these problems.

While I agree that frequent power loss is NOT something a database
should be exposed to, a properly setup machine with a properly
functioning journalling file system should not experience these
problems. Might be time to check the drive subsystem to make sure it's
properly fsyncing data.