From: Thomas SIMON <tsimon@neteven.com>
To: weishan.ang@gmail.com
Cc: pgsql-admin@postgresql.org <pgsql-admin@postgresql.org>
Subject: Re: Performances issues with SSD volume ?
Date: Mon, 18 May 2015 16:21:12 +0200
Message-ID: <5559F558.6050307@neteven.com> (raw)
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Hi Wei,
Yes i'm using RAID (megacli card), battery is ok, i had already checked
BBU :)
Cheers
Thomas
Le 18/05/2015 15:52, Wei Shan a écrit :
>
> Hi Thomas,
>
> This is just a wild guess. Are you using hardware RAID? Is the cache
> battery still working?
>
> Cheers
>
> On 18 May 2015 9:36 pm, "Thomas SIMON" <tsimon@neteven.com
> <mailto:tsimon@neteven.com>> wrote:
>
> Hi matheus,
> thanks for reply.
>
> Kernel is slightly different ; with a 3.10.23-xxxx-std-ipv6-64
> kernel (OVH kernel) on HDD server, and 3.2.65-1+deb7u1 kernel on
> SSD server.
> I'm using debian wheezy on both servers.
>
> I didn't changed the 2 parameters you talk about.
>
> Thanks,
>
> Thomas
>
> Le 18/05/2015 15:13, Matheus de Oliveira a écrit :
>>
>> On Mon, May 18, 2015 at 10:05 AM, Thomas SIMON
>> <tsimon@neteven.com <mailto:tsimon@neteven.com>> wrote:
>>
>> After the change, I had the following behavior, and I don't
>> understand why : everything seems to work fine (load is ~6/7,
>> when it was previously ~25/30 on the HDD server), so the SSD
>> server is faster than the HDD one, and my apps run faster
>> too, but after some time (can be 5 minutes or 2 hours), the
>> load average increases suddently (can reach 150 !) and does
>> not decrease, so postgres and my application are almost
>> unusable. (even small requests are in statement timeout)
>>
>>
>> Before we go mad, what is the OS/kernel/distro that you are
>> using? Did it change from the previous one?
>>
>> If Linux, have you disabled transparent_huge_pages and
>> zone_reclaim_mode (two known problematic Linux features)?
>>
>> Best regards,
>> --
>> Matheus de Oliveira
>> Analista de Banco de Dados
>> Dextra Sistemas - MPS.Br nível F!
>> www.dextra.com.br/postgres <http://www.dextra.com.br/postgres/;
>>
>
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To: pgsql-admin@postgresql.org
Cc: tsimon@neteven.com, weishan.ang@gmail.com
Subject: Re: Performances issues with SSD volume ?
In-Reply-To: <5559F558.6050307@neteven.com>
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