From: Scott Carey <scott@richrelevance.com>
To: Mark Kirkwood <markir@paradise.net.nz>
To: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: Raid 10 chunksize
Date: Thu, 26 Mar 2009 14:49:05 -0700
Message-ID: <C5F14661.3C9C%scott@richrelevance.com> (raw)
In-Reply-To: <49CB047E.3090909@paradise.net.nz>
On 3/25/09 9:28 PM, "Mark Kirkwood" <markir@paradise.net.nz> wrote:
> I wrote:
>> Scott Marlowe wrote:
>>
>>>
>>> Can you try changing the chunksize on the test box you're testing on
>>> to see if that helps?
>>>
>>>
>>
>> Yes - or I am hoping to anyway (part of posting here was to collect
>> some outside validation for the idea). Thanks for your input!
>>
>
> Rebuilt with 64K chunksize:
>
> transaction type: TPC-B (sort of)
> scaling factor: 100
> number of clients: 24
> number of transactions per client: 12000
> number of transactions actually processed: 288000/288000
> tps = 866.512162 (including connections establishing)
> tps = 866.651320 (excluding connections establishing)
>
>
> So 64K looks quite a bit better. I'll endeavor to try out 256K next week
> too.
Just go all the way to 1MB, md _really_ likes 1MB chunk sizes for some
reason. Benchmarks right and left on google show this to be optimal. My
tests with md raid 0 over hardware raid 10's ended up with that being
optimal as well.
Greg's notes on aligning partitions to the chunk are key as well.
>
> Mark
>
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To: pgsql-performance@postgresql.org
Cc: scott@richrelevance.com, markir@paradise.net.nz
Subject: Re: Raid 10 chunksize
In-Reply-To: <C5F14661.3C9C%scott@richrelevance.com>
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