Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TicMh-0006xs-4d for pgsql-performance@arkaria.postgresql.org; Wed, 12 Dec 2012 02:48:07 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1TicMg-000813-CV for pgsql-performance@arkaria.postgresql.org; Wed, 12 Dec 2012 02:48:06 +0000 Received: from makus.postgresql.org ([98.129.198.125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TicMe-00080x-U4 for pgsql-performance@postgresql.org; Wed, 12 Dec 2012 02:48:05 +0000 Received: from outmail149084.authsmtp.net ([62.13.149.84]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TicMd-0003xa-0T for pgsql-performance@postgresql.org; Wed, 12 Dec 2012 02:48:04 +0000 Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt8.authsmtp.com (8.14.2/8.14.2/Kp) with ESMTP id qBC2m04V082736; Wed, 12 Dec 2012 02:48:00 GMT Received: from ayaki.localdomain (58-7-194-83.dyn.iinet.net.au [58.7.194.83]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id qBC2lr5w089329 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Wed, 12 Dec 2012 02:47:56 GMT Message-ID: <50C7F057.70309@2ndQuadrant.com> Date: Wed, 12 Dec 2012 10:47:51 +0800 From: Craig Ringer Organization: 2nd Quadrant User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Evgeny Shishkin CC: =?windows-1252?Q?Niels_Kristian_Schj=F8dt?= , Jeff Janes , "pgsql-performance@postgresql.org" Subject: Re: Do I have a hardware or a software problem? References: <8F7661E7-D6D4-4334-8C6A-A8B6C56A2C3F@autouncle.com> <50C7351C.30407@2ndQuadrant.com> <4507A68A-3CD5-4283-AFA5-1C0593427E14@autouncle.com> <67FBF3AF-5C6A-45D4-9206-7257C8C01C5E@gmail.com> <50C7D7D2.4070605@2ndQuadrant.com> <2BCB6843-1396-42C9-A5BF-21C7C978FF4B@gmail.com> <50C7DDDE.1000000@2ndQuadrant.com> <3ADBD9A3-966F-40E8-AF78-0F2093D79BEE@gmail.com> <50C7E598.2070902@2ndQuadrant.com> <8A08ED7E-CF78-4F40-ACF1-1C87CEBBD00A@gmail.com> In-Reply-To: <8A08ED7E-CF78-4F40-ACF1-1C87CEBBD00A@gmail.com> X-Enigmail-Version: 1.4.6 Content-Type: multipart/alternative; boundary="------------060702020401060503090703" X-Server-Quench: 5662aa43-4406-11e2-b10b-0025903375e2 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCdxZQATClZeVg0b BQteCiN5VAwpPBRK HVkIKg5MJUcNSQVJ NksachtFaQdbaVxS HGQLWlZEUF97XWR/ bgIfaA1DZVRPVgF0 WEtWQFdQERppT11z dRxCEBw1dw1Pe3x5 K0RnWXVbEkF8c0Qs E0pXCGkCZWF9aWFK Ul0KdgMGbQNKfBpM alN8U3ZYYytlM3Bw LDceBR4WBxBqYAhS CiBFLVsMTA4CVj41 XRwdFC8iVUofDyx7 NBsoNkEVBktZKl81 O18sXAVw X-Authentic-SMTP: 61633235383639.1019:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 58.7.194.83/2525 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Pg-Spam-Score: -2.6 (--) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org This is a multi-part message in MIME format. --------------060702020401060503090703 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit On 12/12/2012 10:13 AM, Evgeny Shishkin wrote: > > Yes, i am aware of this issue. Never experienced this neither on intel > 520, no ocz vertex 3. > I wouldn't trust either of those drives. The 520 doesn't have Intel's " Enhanced Power Loss Data Protection"; it's going to lose its buffers if it loses power. Similarly, the Vertex 3 doesn't have any kind of power protection. See: http://www.intel.com/content/www/us/en/solid-state-drives/ssd-320-series-power-loss-data-protection-brief.html http://ark.intel.com/products/family/56572/Intel-SSD-500-Family http://www.ocztechnology.com/res/manuals/OCZ_SSD_Breakdown_Q2-11_1.pdf The only way I'd use those for a production server was if I had synchronous replication running to another machine with trustworthy, durable storage - and if I didn't mind some downtime to restore the corrupt DB from the replica after power loss. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services --------------060702020401060503090703 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 7bit
On 12/12/2012 10:13 AM, Evgeny Shishkin wrote:

Yes, i am aware of this issue. Never experienced this neither on intel 520, no ocz vertex 3.


I wouldn't trust either of those drives. The 520 doesn't have Intel's " Enhanced Power Loss Data Protection"; it's going to lose its buffers if it loses power. Similarly, the Vertex 3 doesn't have any kind of power protection. See:

http://www.intel.com/content/www/us/en/solid-state-drives/ssd-320-series-power-loss-data-protection-brief.html
http://ark.intel.com/products/family/56572/Intel-SSD-500-Family

http://www.ocztechnology.com/res/manuals/OCZ_SSD_Breakdown_Q2-11_1.pdf

The only way I'd use those for a production server was if I had synchronous replication running to another machine with trustworthy, durable storage - and if I didn't mind some downtime to restore the corrupt DB from the replica after power loss.

-- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services
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