Message-ID: <513529B5.9060205@catalyst.net.nz>
Date: Tue, 05 Mar 2013 12:09:41 +1300
From: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
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To: Steven Crandell <steven.crandell@gmail.com>
CC: Jean-David Beyer <jeandavid8@verizon.net>,
	pgsql-performance@postgresql.org
Subject: Re: hardware upgrade, performance degrade?
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On 05/03/13 11:54, Steven Crandell wrote:
> Here's our hardware break down.
>
> The logvg on the new hardware  is 30MB/s slower (170 MB/s vs 200 MB/s )
> than the logvg on the older hardware which was an immediately interesting
> difference but we have yet to be able to create a test scenario that
> successfully implicates this slower log speed in our problems. That is
> something we are actively working on.
>
>
> Old server hardware:
>          Manufacturer: Dell Inc.
>          Product Name: PowerEdge R810
>          4x Intel(R) Xeon(R) CPU           E7540  @ 2.00GHz
>          32x16384 MB 1066 MHz DDR3
>          Controller 0: PERC H700 - 2 disk RAID-1 278.88 GB rootvg
>          Controller 1: PERC H800 - 18 disk RAID-6 2,178.00 GB datavg, 4
> drive RAID-10 272.25 GB logvg, 2 hot spare
>          2x 278.88 GB 15K SAS on controller 0
>          24x 136.13 GB 15K SAS on controller 1
>
> New server hardware:
>         Manufacturer: Dell Inc.
>          Product Name: PowerEdge R820
>          4x Intel(R) Xeon(R) CPU E5-4620 0 @ 2.20GHz
>          32x32 GB 1333 MHz DDR3
>          Controller 0: PERC H710P  - 4 disk RAID-6 557.75 GB rootvg
>          Controller 1: PERC H810    - 20 disk RAID-60 4,462.00 GB datavg, 2
> disk RAID-1  278.88 GB logvg, 2 hot spare
>          28x278.88 GB 15K SAS drives total.
>
>
> On Sun, Mar 3, 2013 at 1:34 PM, Jean-David Beyer <jeandavid8@verizon.net>wrote:
>

Right - It is probably worth running 'pg_test_fsync' on the two logvg's 
and comparing the results. This will tell you if the commit latency is 
similar or not on the two disk systems.

One other difference that springs immediately to mind is that datavg is 
an 18 disk RAID 6 on the old system and a 20 disk RAID 60 on the new 
one...so you have about 1/2 the io performance right there.

Cheers

Mark


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