From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Josef 'Jeff' Sipek" Subject: Re: How do I tell if my partition is aligned for a 64k/RAID-6? Date: Sat, 27 Dec 2008 08:38:24 -0500 Message-ID: <20081227133824.GH6284@josefsipek.net> References: <495410F4.5010508@ziu.info> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Justin Piszcz Cc: linux-raid@vger.kernel.org, xfs@oss.sgi.com List-Id: linux-raid.ids On Thu, Dec 25, 2008 at 06:46:37PM -0500, Justin Piszcz wrote: > On Fri, 26 Dec 2008, Michal Soltys wrote: > >> I am not worried about the filesystem as the defaults usually get it right > >> but with parted, this is the first time I had to use it for home use and > >> with RAID-6 I am noticing slower performance with 15 disks (1 is a spare) > >> in RAID-6 (albeit slower 7200 ones, RE3s) than I was getting with 10 > >> raptor150s in RAID-6 (but I had used fdisk there). > >> > >> Justin. > >> > > > > For best effect - partition should start at 1920th sector (stripe width > > boundary), and su/sw should be appropriately set - su=64k,sw=13 in your > > case. Parted shows the values normally - from the beginning of the volume, 0 > > based. > > > > > > ps. > > > > I dropped some of CCs. > > Thanks. It looks like you made why big partition. Why bother with partitioning at all? If you just use the whole device, you _will_ be aligned properly if you tell mkfs.xfs about the stripe unit/width. Josef 'Jeff' Sipek. -- All science is either physics or stamp collecting. - Ernest Rutherford _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs