On 06/17/2013 01:34 PM, Stuart Bishop wrote:
>>> I've since heard that 3.4 also fixes this issue as well.
>>>
>>> What are you using for your IO on these boxes?
>>
>> I was able to demonstrate it over iSCSI to a Nimble Storage SAN as well as
>> DAS with 2 drive RAID 1 for xlogs and 8 drive RAID 10 for data (DL385 G7).
>
>
> This might sound familiar:
>
> http://postgresql.1045698.n5.nabble.com/Ubuntu-12-04-3-2-Kernel-Bad-for-PostgreSQL-Performance-td5735284.html
>
> tl;dr for that thread seems to be a driver problem (fusionIO?), I'm
> unsure if Ubuntu specific or in the upstream kernel.
If it is a driver problem, then two different drivers were buggy the
Nimble Storage San driver (iSCSI) as well as the DL385 DAS (LSI). Anyway
the upgrade to 3.9 makes the problem disappear. There are other insights
in the comments of the blog post.
JD
>
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