On 06/06/2013 03:48 PM, Scott Marlowe wrote:
>
> On Thu, Jun 6, 2013 at 4:35 PM, Joshua D. Drake <jd@commandprompt.com> wrote:
>>
>> Hello,
>>
>> I had the distinct displeasure of staying up entirely too late with a
>> customer this week because they upgraded to 12.04 and immediately
>> experienced a huge performance regression. In the process they also upgraded
>> to PostgreSQL 9.1 from 8.4. There were a lot of knobs to change/fix/modify
>> because of this. However, nothing I did fixed the problem. Until... I
>> upgraded the kernel.
>>
>> Upgrading from 3.2Precise to the 3.9.4 kernel produced the following
>> results:
>
> 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).
JD
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