X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 75FDA9DCC0B for ; Tue, 6 Dec 2005 17:36:04 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 97854-04 for ; Tue, 6 Dec 2005 17:36:05 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from campbell-lange.net (campbell-lange.net [217.147.82.41]) by postgresql.org (Postfix) with ESMTP id 40E669DCBEC for ; Tue, 6 Dec 2005 17:36:02 -0400 (AST) Received: from rory by localhost.localdomain with local (Exim 4.54) id 1EjkU3-0003qx-JZ; Tue, 06 Dec 2005 21:36:23 +0000 Date: Tue, 6 Dec 2005 21:36:23 +0000 From: Rory Campbell-Lange To: August Zajonc Cc: pgsql-performance@postgresql.org Subject: Re: LVM and Postgres Message-ID: <20051206213623.GD14427@campbell-lange.net> References: <20051206093818.GE6708@campbell-lange.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.666 required=5 tests=[AWL=0.666] X-Spam-Score: 0.666 X-Spam-Level: X-Archive-Number: 200512/199 X-Sequence-Number: 16020 Hi August. Thanks very much for your mail. On 06/12/05, August Zajonc (augustz@augustz.com) wrote: > Rory Campbell-Lange wrote: > >The server has a 250GB RAID10 (LSI 320-I + BBU) volume which I am > >thinking of slicing up in the following way (Linux 2.6 kernel): > > > > / : ext3 : 47GB (root, home etc) > > /boot : ext3 : 1GB > > /tmp : ext2 : 2GB > > /usr : ext3 : 4GB > > /var : ext3 : 6GB > > ----------------------- > > 60GB > > > > VG : 190GB approx > > ----------------------- > > Initially divided so: > > /data : ext3 : 90GB > > /postgres : xfs : 40GB > > > >This gives me left over space of roughly 60GB to extend into on the > >volume group, which I can balance between the /data and /postgres > >logical volumes as needed. > > It looks like you are using fast disks and xfs for filesystem on the > /postgresql partition. That's nice. > > How many disks in the array? Four. > One thing you miss is sticking a bunch of sequential log writes on a > separate spindle as far as I can see with this? WAL / XFS (i think) both > have this pattern. If you've got a fast disk and can do BBU write > caching your WAL writes will hustle. Yes, we don't have any spare disks unfortunately. We have enabled the BBU write, so we are hoping for good performance. I'd be grateful for some advice on dd/bonnie++ tests for checking this. > Others can probably speak a bit better on any potential speedups. I'd better test extending the Logical Volumes too! Many thanks Rory