Re: Lost rows/data corruption?

Marco Colombo wrote:
> On Wed, 16 Feb 2005, Andrew Hall wrote:
>
>> fsync is on for all these boxes. Our customers run their own hardware
>> with many different specification of hardware in use. Many of our
>> customers don't have UPS, although their power is probably pretty
>> reliable (normal city based utilities), but of course I can't
>> guarantee they don't get an outage once in a while with a thunderstorm
>> etc.
>
>
> I see. Well I can't help much, then, I don't run PG on XFS. I suggest
> testing
> on a different FS, to exclude XFS problems. But with fsync on, the FS has
> very little to do with reliability, unless it _lies_ about fsync(). Any
> FS should return from fsync only after data is on disc, journal or not
> (there might be issues with meta-data, but it's hardly a problem with PG).
>
> It's more likely the hardware (IDE disks) lies about data being on plate.
> But again that's only in case of sudden poweroffs.

Do you happen to have the same type disks in all these systems? That
could point to a disk cache "problem" (f.e. the disks lying about having
written data from the cache to disk).

Or do you use the same disk parameters on all these machines? Have you
tried using the disks w/o write caching and/or in synchronous mode
(contrary to "async").

--
Alban Hertroys
MAG Productions

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