Re: Tuning PostgreSQL

On 21 Jul 2003 at 18:09, Ang Chin Han wrote:

> Shridhar Daithankar wrote:
> > On 21 Jul 2003 at 11:23, Alexander Priem wrote:
>
> >>I use ext3 filesystem, which probably is not the best performer, is it?
> >
> > No. You also need to check ext2, reiser and XFS. There is no agreement between
> > users as in what works best. You need to benchmark and decide.
>
> Need? Maybe I'm a bit disillusioned, but are the performances between
> the filesystems differ so much as to warrant the additional effort?
> (e.g. XFS doesn't come with Red Hat 9 -- you'll have to patch the
> source, and compile it yourself).

Well, the benchmarking is not to prove which filesystem is fastest and feature
rich but to find out which one suits your needs best.

> Benchmarking it properly before deployment is tough: are the test load
> on the db/fs representative of actual load? Is 0.5% reduction in CPU
> usage worth it? Did you test for catastrophic failure by pulling the
> plug during write operations (ext2) to test if the fs can handle it? Is
> the code base for the particular fs stable enough? Obscure bugs in the fs?

Well, that is what that 'benchmark' is supposed to find out. Call it pre-
deployment testing or whatever other fancy name one sees fit. But it is a must
in almost all serious usage.

> For the record, we tried several filesystems, but stuck with 2.4.9's
> ext3 (Red Hat Advanced Server). Didn't hit a load high enough for the
> filesystem choices to matter after all. :(

Good for you. You have time at hand to find out which one suits you best. Do
the testing before you have load that needs another FS..:-)

Bye
 Shridhar

--
It would be illogical to assume that all conditions remain stable.        -- Spock, "The Enterprise" Incident",
stardate5027.3