Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1Xz3lo-000435-IM for pgsql-performance@arkaria.postgresql.org; Thu, 11 Dec 2014 13:27:04 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1Xz3lo-00040w-35 for pgsql-performance@arkaria.postgresql.org; Thu, 11 Dec 2014 13:27:04 +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 1Xz3ln-00040q-BZ for pgsql-performance@postgresql.org; Thu, 11 Dec 2014 13:27:03 +0000 Received: from mx1.opinioni.net ([213.187.10.46]) by magus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1Xz3lj-0003nd-Fb for pgsql-performance@postgresql.org; Thu, 11 Dec 2014 13:27:01 +0000 Received: from localhost (localhost [127.0.0.1]) by mx1.opinioni.net (Postfix) with ESMTP id 24F312B51B3; Thu, 11 Dec 2014 14:27:00 +0100 (CET) Received: from mx1.opinioni.net ([127.0.0.1]) by localhost (opinioni.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id re7Tb97Uzyed; Thu, 11 Dec 2014 14:27:00 +0100 (CET) Received: from [192.168.1.50] (78-134-6-72.v4.ngi.it [78.134.6.72]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mx1.opinioni.net (Postfix) with ESMTPS id CDD5A5DB2; Thu, 11 Dec 2014 14:26:59 +0100 (CET) Message-ID: <54899BA1.50908@opinioni.net> Date: Thu, 11 Dec 2014 14:26:57 +0100 From: Andrea Suisani User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Evgeniy Shishkin , Andrea Suisani CC: mfatticcioni@mbigroup.it, pgsql-performance@postgresql.org Subject: Re: Tuning the configuration 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> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit 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 On 12/11/2014 01:11 PM, Evgeniy Shishkin wrote: > >> 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. Well since Malia had already used the 4 sas hd for the DB, I thought that it'd be quite quick to setup a raid1 array (even at software level, e.g. using md), placing pg_xlog in such array and measure the performance. As a following step, depending on the time constraints involved, Malia could rearrange the disk setup enterly and use the SAS disks as location for pg_xlog. Andrea -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance