| From: | Mark Kirkwood <markir(at)paradise(dot)net(dot)nz> |
|---|---|
| To: | Dan Gorman <dgorman(at)hi5(dot)com> |
| Cc: | Luke Lonergan <llonergan(at)greenplum(dot)com>, "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>, "Craig A(dot) James" <cjames(at)modgraph-usa(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Reliability recommendations |
| Date: | 2006-02-25 01:18:31 |
| Message-ID: | 43FFB067.2070406@paradise.net.nz |
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| Lists: | pgsql-performance |
Dan Gorman wrote:
> All,
>
> Was that sequential reads? If so, yeah you'll get 110MB/s? How big was
> the datafile size? 8MB? Yeah, you'll get 110MB/s. 2GB? No, they can't
> sustain that. There are so many details missing from this test that
> it's hard to have any context around it :)
>
Actually they can. Datafile size was 8G, machine had 2G RAM (i.e.
datafile 4 times memory). The test was for a sequential read with 8K
blocks. I believe this is precisely the type of test that the previous
posters were referring to - while clearly, its not a real-world measure,
we are comparing like to like, and as such terrible results on such a
simple test are indicative of something 'not right'.
regards
Mark
P.s. FWIW - I'm quoting a test from a few years ago - the (same) machine
now has 4 RAID0 ata disks and does 175MB/s on the same test....
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