Received: from localhost (unknown [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 7592D2E006B for ; Thu, 17 Jan 2008 17:07:12 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 45649-03 for ; Thu, 17 Jan 2008 17:07:02 -0400 (AST) Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.183]) by postgresql.org (Postfix) with ESMTP id E77AB2E34FF for ; Thu, 17 Jan 2008 17:07:04 -0400 (AST) Received: by wa-out-1112.google.com with SMTP id m38so1388458waf.5 for ; Thu, 17 Jan 2008 13:07:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=NmmDvLT0s+alXheVTtfcCpBR27IbquxD/6NBYEWfjPI=; b=PsVoxYAhp/hdcE3O5XCqbht9Xm1eTSF73W2mpxCdy42QJOP9ycdFq1VF+aTGx9W7ebPPkBQTOu0NpcBBE/pish+KLKqwBDLGVnxAlZD516W1uvWPOD9WcI4mfX2C/koqv6GBH5jggJ0/lqJZQM8eodvHvegqMxj4+EqSvmFqvek= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=HL7HxoEDN5PE8EJDijEVIN8rIGmfAAeKN2pNd3Fzp+KqoFu2jX4jUFQvB+B6l7Gb4+mKNaMsOLsXG8sHre0P6tsyEWEi9B7PWC/7ei7L6PFdS2nx/HFcOvKKskT7Rq0OkCuHIrLQWwRER9fDZPg74MMtFyFy4EYjVQE1DzOFtQk= Received: by 10.114.37.1 with SMTP id k1mr283850wak.6.1200604022458; Thu, 17 Jan 2008 13:07:02 -0800 (PST) Received: by 10.114.133.5 with HTTP; Thu, 17 Jan 2008 13:07:02 -0800 (PST) Message-ID: Date: Thu, 17 Jan 2008 15:07:02 -0600 From: "Scott Marlowe" To: "Sean Davis" Subject: Re: [OT] RAID controllers blocking one another? Cc: pgsql-performance@postgresql.org In-Reply-To: <264855a00801171217m4e6211e6y5f4d0e12ce86db5c@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <264855a00801171217m4e6211e6y5f4d0e12ce86db5c@mail.gmail.com> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200801/140 X-Sequence-Number: 28379 On Jan 17, 2008 2:17 PM, Sean Davis wrote: > We have a machine that serves as a fileserver and a database server. Our > server hosts a raid array of 40 disk drives, attached to two3-ware cards, > one 9640SE-24 and one 9640SE-16. We have noticed that activity on one > controller blocks access on the second controller, not only for disk-IO but > also the command line tools which become unresponsive for the inactive > controller. The controllers are sitting in adjacent PCI-express slots on a > machine with dual-dual AMD and 16GB of RAM. Has anyone else noticed issues > like this? Throughput for either controller is a pretty respectable > 150-200MB/s writing and somewhat faster for reading, but the "blocking" is > problematic, as the machine is serving multiple purposes. > > I know this is off-topic, but I know lots of folks here deal with very large > disk arrays; it is hard to get real-world input on machines such as these. Sounds like they're sharing something they shouldn't be. I'm not real familiar with PCI-express. Aren't those the ones that use up to 16 channels for I/O? Can you divide it to 8 and 8 for each PCI-express slot in the BIOS maybe, or something like that? Just a SWAG.