From owner-freebsd-stable@FreeBSD.ORG Wed Aug 29 19:10:46 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 379F816A418 for ; Wed, 29 Aug 2007 19:10:46 +0000 (UTC) (envelope-from krion@voodoo.bawue.com) Received: from voodoo.bawue.com (voodoo.bawue.com [212.9.161.119]) by mx1.freebsd.org (Postfix) with ESMTP id F0DE613C481 for ; Wed, 29 Aug 2007 19:10:45 +0000 (UTC) (envelope-from krion@voodoo.bawue.com) Received: from krion by voodoo.bawue.com with local (Exim 4.67 (FreeBSD)) (envelope-from ) id 1IQSVP-000FwG-CE; Wed, 29 Aug 2007 20:43:07 +0200 Date: Wed, 29 Aug 2007 20:43:07 +0200 From: Kirill Ponomarew To: Vivek Khera Message-ID: <20070829184306.GC42906@voodoo.bawue.com> References: <31BB09D7-B58A-47AC-8DD1-6BB8141170D8@khera.org> <94ECF72B-B0E9-492C-8279-29989FAAE19C@khera.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <94ECF72B-B0E9-492C-8279-29989FAAE19C@khera.org> X-NIC-HDL: KP869-RIPE Cc: FreeBSD Stable Subject: Re: large RAID volume partition strategy X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Aug 2007 19:10:46 -0000 On Wed, Aug 29, 2007 at 10:07:19AM -0400, Vivek Khera wrote: > > On Aug 17, 2007, at 10:44 PM, Ivan Voras wrote: > >> >> fdisk and bsdlabels both have a limit: because of the way they store the >> data about the disk space they span, they can't store values that >> reference space > 2 TB. In particular, every partition must start at an >> offset <= 2 TB, and cannot be larger than 2 TB. > > Thanks. This is good advice (along with your other note about doing it in > the RAID volume manager). Nearly everyone else decided to jump on the raid > level instead and spew forth the "RAID10 is better for database" party > line. Well to you folks: once you have 1Gb cache and a lot of disks, there > is not much difference between RAID10 and RAID5 or RAID6 in my testing. What type I/O did you test, random read/writes, sequential writes ? The performance of RAID group always depends on what software you run on your RAID group. If it's database, be prepared for many random read/writes, hence dd(1) tests would be useless. > I ended up making 6 RAID volumes across all the disks to maximize spindle > counts and strip the data at 16kB. This seems to work well, and I can > assign the other partition as I need later on. > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" -Kirill