Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 1BBA21337B9D for ; Fri, 28 Jan 2011 17:33:38 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 42969-04 for ; Fri, 28 Jan 2011 21:33:31 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mxtip01-umsystem-out.um.umsystem.edu (mxtip01-umsystem-out.um.umsystem.edu [209.106.229.49]) by mail.postgresql.org (Postfix) with ESMTP id 41B2F1337B9C for ; Fri, 28 Jan 2011 17:33:30 -0400 (AST) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArMGANzEQk3RauUo/2dsb2JhbACCQqFcZXOxVohphU8EhRiKUwY Received: from um-tsmtpout1.um.umsystem.edu ([209.106.229.40]) by mxtip01-missouri-out.um.umsystem.edu with ESMTP; 28 Jan 2011 15:33:29 -0600 Received: from um-tsmtpout1.um.umsystem.edu ([209.106.229.35]) by um-tsmtpout1.um.umsystem.edu with Microsoft SMTPSVC(6.0.3790.4675); Fri, 28 Jan 2011 15:33:29 -0600 Received: from [128.206.129.163] ([128.206.129.163]) by um-tsmtpout1.um.umsystem.edu over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Fri, 28 Jan 2011 15:33:28 -0600 Message-ID: <4D433628.6010209@missouri.edu> Date: Fri, 28 Jan 2011 15:33:28 -0600 From: Robert Schnabel User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv:1.9.2.13) Gecko/20101207 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: Scott Carey CC: Alan Hodgson , "pgsql-performance@postgresql.org" Subject: Re: How to best use 32 15k.7 300GB drives? References: In-Reply-To: Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 28 Jan 2011 21:33:28.0922 (UTC) FILETIME=[00E1B3A0:01CBBF33] X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.176 tagged_above=-10 required=5 tests=BAYES_00=-1.9, HTML_MESSAGE=0.001, MIME_HTML_ONLY=0.723 X-Spam-Level: X-Archive-Number: 201101/330 X-Sequence-Number: 42117
On 1/28/2011 11:44 AM, Scott Carey wrote:

On 1/27/11 4:11 PM, "Alan Hodgson" <ahodgson@simkin.ca> wrote:

On January 27, 2011, Robert Schnabel <schnabelr@missouri.edu> wrote:

> So my questions are 1) am I'm crazy for doing this, 2) would you change

> anything and 3) is it acceptable to put the xlog & wal (and perhaps tmp

> filespace) on a different controller than everything else? Please keep

> in mind I'm a geneticist who happens to know a little bit about

> bioinformatics and not the reverse. :-)

>

Putting the WAL on a second controller does help, if you're write-heavy.

I tried separating indexes and data once on one server and didn't really notice that it helped much. Managing the space was problematic. I would suggest putting those together on a single RAID-10 of all the 300GB drives (minus a spare). It will probably outperform separate arrays most of the time, and be much easier to manage.

If you go this route, I suggest two equally sized RAID 10's on different controllers fir index + data, with software raid-0 on top of that. RAID 10 will max out a controller after 6 to 10 drives, usually. Using the OS RAID 0 to aggregate the throughput of two controllers works great.

WAL only has to be a little bit faster than your network in most cases. I've never seen it be a bottleneck on large bulk loads if it is on its own controller with 120MB/sec write throughput. I suppose a bulk load from COPY might stress it a bit more, but CPU ends up the bottleneck in postgres once you have I/O hardware this capable.

Do you mean 14 drives in one box as RAID10's on one controller, then 14 drives in the other box on a second controller, then software RAID0 each of the two RAID10's together essentially as a single 4 TB array? Would you still recommend doing this with Windows?
Bob