Re: Postgresql Performance on an HP DL385 and

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Luke,

I thought so. In my test, I tried to be fair/equal since my Sun box has two 4-disc arrays each on their own channel. So, I just used one of them which should be a little slower than the 6-disc with 192MB cache.

Incidently, the two internal SCSI drives, which are on the 6i adapter, generated a TPS of 18.

I thought this server would impressive from notes I've read in the group. This is why I thought I might be doing something wrong. I stumped which way to take this. There is no obvious fault but something isn't right.

Steve

On 8/8/06, Luke Lonergan <LLonergan@xxxxxxxxxxxxx> wrote:
Steve,

> Sun box with 4-disc array (4GB RAM. 4 167GB 10K SCSI RAID10
> LSI MegaRAID 128MB). This is after 8 runs.
>
> dbserver-dual-opteron-centos,08/08/06,Tuesday,20,us,12,2,5
> dbserver-dual-opteron-centos,08/08/06,Tuesday,20,sy,59,50,53
> dbserver-dual-opteron-centos,08/08/06,Tuesday,20,wa,1,0,0
> dbserver-dual-opteron-centos,08/08/06,Tuesday,20,id,45,26,38
>
> Average TPS is 75
>
> HP box with 8GB RAM. six disc array RAID10 on SmartArray 642
> with 192MB RAM. After 8 runs, I see:
>
> intown-vetstar-amd64,08/09/06,Tuesday,23,us,31,0,3
> intown-vetstar-amd64,08/09/06,Tuesday,23,sy,16,0,1
> intown-vetstar-amd64,08/09/06,Tuesday,23,wa,99,6,50
> intown-vetstar-amd64,08/09/06,Tuesday,23,id,78,0,42
>
> Average TPS is 31.

Note that the I/O wait (wa) on the HP box high, low and average are all
*much* higher than on the Sun box.  The average I/O wait was 50% of one
CPU, which is huge.  By comparison there was virtually no I/O wait on
the Sun machine.

This is indicating that your HP machine is indeed I/O bound and
furthermore is tying up a PG process waiting for the disk to return.

- Luke



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