From: Joshua D. Drake <jd@commandprompt.com>
To: Brad Nicholson <bnichols@ca.afilias.info>
Cc: pgsql-performance@postgresql.org
Subject: Re: Investigating IO Saturation
Date: Tue, 24 Jan 2006 09:09:18 -0800
Message-ID: <43D65F3E.9040107@commandprompt.com> (raw)
In-Reply-To: <43D65DFC.2040107@ca.afilias.info>
References: <43D65736.9020905@ca.afilias.info>
<43D658D3.5070808@commandprompt.com>
<43D65DFC.2040107@ca.afilias.info>
Brad Nicholson wrote:
> Joshua D. Drake wrote:
>
>> Brad Nicholson wrote:
>>
>>> I'm investigating a potential IO issue. We're running 7.4 on AIX
>>> 5.1. During periods of high activity (reads, writes, and vacuums),
>>> we are seeing iostat reporting 100% disk usage. I have a feeling
>>> that the iostat numbers are misleading. I can make iostat usage
>>> jump from less than 10% to greater than 95% by running a single
>>> vacuum against a moderate sized table (no noticeable change in the
>>> other activity).
>>>
>> Well that isn't surprising. Vacuum is brutal especially on 7.4 as
>> that is pre background writer. What type of IO do you have available
>> (RAID, SCSI?)
>>
> Data LUN is RAID 10, wal LUN is RAID 1.
How many disks?
>
>
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To: pgsql-performance@postgresql.org
Cc: jd@commandprompt.com, bnichols@ca.afilias.info
Subject: Re: Investigating IO Saturation
In-Reply-To: <43D65F3E.9040107@commandprompt.com>
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