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 A096A9DC850 for ; Mon, 30 Jan 2006 01:35:12 -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 93428-08 for ; Mon, 30 Jan 2006 01:35:11 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from mail.bway.net (xena.bway.net [216.220.96.26]) by postgresql.org (Postfix) with ESMTP id 2590F9DC843 for ; Mon, 30 Jan 2006 01:35:09 -0400 (AST) Received: (qmail 93872 invoked by uid 0); 30 Jan 2006 05:35:09 -0000 Received: from unknown (HELO ?192.168.0.41?) (spork@bway.net@216.220.116.154) by smtp.bway.net with (DHE-RSA-AES256-SHA encrypted) SMTP; 30 Jan 2006 05:35:09 -0000 Date: Mon, 30 Jan 2006 00:35:12 -0500 (EST) From: Charles Sprickman X-X-Sender: spork@spork-book.local To: Luke Lonergan cc: hubert depesz lubaczewski , pgsql-performance@postgresql.org Subject: Re: Huge Data sets, simple queries In-Reply-To: <3E37B936B592014B978C4415F90D662D023F28D9@MI8NYCMAIL06.Mi8.com> Message-ID: References: <3E37B936B592014B978C4415F90D662D023F28D9@MI8NYCMAIL06.Mi8.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.096 required=5 tests=[AWL=0.096] X-Spam-Score: 0.096 X-Spam-Level: X-Archive-Number: 200601/473 X-Sequence-Number: 16951 On Sun, 29 Jan 2006, Luke Lonergan wrote: > In fact, in our testing of various host-based SCSI RAID adapters (LSI, > Dell PERC, Adaptec, HP SmartArray), we find that *all* of them > underperform, most of them severely. [snip] > The important lesson we've learned is to always test the I/O subsystem > performance - you can do so with a simple test like: > time bash -c "dd if=/dev/zero of=bigfile bs=8k count=4000000 && sync" > time dd if=bigfile of=/dev/null bs=8k I'm curious about this since we're shopping around for something new... I do want to get some kind of baseline to compare new products to. Areca sent me stats on their SCSI->SATA controller and it looks like it maxes out around 10,000 IOPS. I'd like to see how our existing stuff compares to this. I'd especially like to see it in graph form such as the docs Areca sent (IOPS on one axis, block size on the other, etc.). Looking at the venerable Bonnie, it doesn't really seem to focus so much on the number of read/write operations per second, but on big bulky transfers. What are you folks using to measure your arrays? I've been considering using some of our data and just basically benchmarking postgres on various hardware with that, but I cannot compare that to any manufacturer tests. Sorry to meander a bit off topic, but I've been getting frustrated with this little endeavour... Thanks, Charles > - Luke > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq >