Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1XzCMA-0008E6-CJ for pgsql-performance@arkaria.postgresql.org; Thu, 11 Dec 2014 22:37:10 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1XzCM9-0001QU-6T for pgsql-performance@arkaria.postgresql.org; Thu, 11 Dec 2014 22:37:09 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1XzCM8-0001QO-C9 for pgsql-performance@postgresql.org; Thu, 11 Dec 2014 22:37:08 +0000 Received: from mail.exchangemadeeasy.com ([64.72.152.231] helo=smtp.saasmadeeasy.com) by magus.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1XzCM4-0005el-8J for pgsql-performance@postgresql.org; Thu, 11 Dec 2014 22:37:07 +0000 X-Virus-Scanned: by SpamTitan at saasmadeeasy.com Received: from H-EX-01.hosting.local (172.26.114.50) by H-EX-02.hosting.local (172.26.114.51) with Microsoft SMTP Server (TLS) id 15.0.847.32; Thu, 11 Dec 2014 17:36:52 -0500 Received: from H-EX-01.hosting.local ([::1]) by H-EX-01.hosting.local ([fe80::6003:1766:66b1:28ef%15]) with mapi id 15.00.0847.030; Thu, 11 Dec 2014 17:36:52 -0500 From: Eric Pierce To: Evgeniy Shishkin , Andrea Suisani CC: "mfatticcioni@mbigroup.it" , "pgsql-performance@postgresql.org" Subject: Re: Tuning the configuration Thread-Topic: [PERFORM] Tuning the configuration Thread-Index: AQHQFGaVydPtYJaIYkyWc5EaPjVes5yKn7OAgAACZICAAFo5/w== Date: Thu, 11 Dec 2014 22:36:51 +0000 Message-ID: References: <548823F8.4070003@mbigroup.it> <548987D7.7040304@opinioni.net>, <6B084BAC-82C6-410A-88D4-9CDC01DA8C09@gmail.com> In-Reply-To: <6B084BAC-82C6-410A-88D4-9CDC01DA8C09@gmail.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.26.114.251] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Pg-Spam-Score: -1.9 (-) 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 ________________________________________ From: pgsql-performance-owner@postgresql.org on behalf of Evgeniy Shishkin Sent: Thursday, December 11, 2014 7:11 AM To: Andrea Suisani Cc: mfatticcioni@mbigroup.it; pgsql-performance@postgresql.org Subject: Re: [PERFORM] Tuning the configuration > On 11 Dec 2014, at 15:02, Andrea Suisani wrote: > > On 12/10/2014 11:44 AM, Maila Fatticcioni wrote: >> 2- I would like to use the two SDD to store the wal file. Do you think >> it is useful or how should I use them? > > I definitely would give it a try. > > I don't understand the logic behind using drives, > which are best for random io, for sequent io workloads. > Better use 10k sas with BBU raid for wal, money wise. Very much agree with this. Because SSD is fast doesn't make it suited for = certain things, and a streaming sequential 100% write workload is one of th= em. I've worked with everything from local disk to high-end SAN and even = at the high end we've always put any DB logs on spinning disk. RAID1 is ge= nerally sufficient. SSD is king for read heavy random I/O workload. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance --=20 Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance