Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UfENW-00058j-0Z for pgsql-performance@arkaria.postgresql.org; Wed, 22 May 2013 19:07:14 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1UfENU-0006Ee-Uf for pgsql-performance@arkaria.postgresql.org; Wed, 22 May 2013 19:07:12 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UfENK-00065x-EF for pgsql-performance@postgresql.org; Wed, 22 May 2013 19:07:02 +0000 Received: from 30.55.colo.spiretech.net ([69.168.55.30] helo=lists.commandprompt.com) by makus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1UfEND-00033k-KF for pgsql-performance@postgresql.org; Wed, 22 May 2013 19:07:01 +0000 Received: from [192.168.1.5] (spinlock.commandprompt.com [69.168.55.30]) by lists.commandprompt.com (Postfix) with ESMTPA id 04787395; Wed, 22 May 2013 12:06:53 -0700 (PDT) Received: from [192.168.1.5] ([71.95.101.172] helo=[192.168.1.5]) by assp.commandprompt.com with ESMTPS(AES256-SHA) (2.1.1); 22 May 2013 12:06:53 -0700 Message-ID: <519D174A.4050703@commandprompt.com> Date: Wed, 22 May 2013 12:06:50 -0700 From: "Joshua D. Drake" Organization: Command Prompt, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Greg Smith CC: sthomas@optionshouse.com, Merlin Moncure , Tomas Vondra , pgsql-performance@postgresql.org Subject: Re: Reliability with RAID 10 SSD and Streaming Replication References: <51957499.6050905@fuzzy.cz> <519991EB.8010208@2ndQuadrant.com> <519A8E29.60702@fuzzy.cz> <519C0EFD.9080002@2ndQuadrant.com> <519CF8CC.1030204@optionshouse.com> <519D0921.9080807@2ndQuadrant.com> In-Reply-To: <519D0921.9080807@2ndQuadrant.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Assp-Version: 2.1.1(11364) on assp.commandprompt.com X-Assp-Client-SSL: yes X-Assp-ID: assp.commandprompt.com m1-49613-08505 X-Assp-Envelope-From: jd@commandprompt.com X-Assp-Intended-For: greg@2ndQuadrant.com X-Assp-Original-Subject: Re: [PERFORM] Reliability with RAID 10 SSD and Streaming Replication X-Pg-Spam-Score: 0.8 (/) 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 On 05/22/2013 11:06 AM, Greg Smith wrote: > I have some moderately fast SSD based transactional systems that are > still using traditional drives with battery-backed cache for the > sequential writes of the WAL volume, where the data volume is on Intel > 710 disks. WAL writes really burn through flash cells, too, so keeping > them on traditional drives can be cost effective in a few ways. That > approach is lucky to hit 10K TPS though, so it can't compete against > what a PCI-E card like the FusionIO drives are capable of. Greg, can you elaborate on the SSD + Xlog issue? What type of burn through are we talking about? JD -- Command Prompt, Inc. - http://www.commandprompt.com/ 509-416-6579 PostgreSQL Support, Training, Professional Services and Development High Availability, Oracle Conversion, Postgres-XC, @cmdpromptinc For my dreams of your image that blossoms a rose in the deeps of my heart. - W.B. Yeats -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance