From mboxrd@z Thu Jan 1 00:00:00 1970 From: keld@keldix.com Subject: Re: raid10n2/xfs setup guidance on write-cache/barrier Date: Thu, 15 Mar 2012 16:25:48 +0100 Message-ID: <20120315152548.GA25194@www5.open-std.org> References: <4F61803A.60009@hardwarefreak.com> <20321.63389.586851.689070@tree.ty.sabi.co.UK> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20321.63389.586851.689070@tree.ty.sabi.co.UK> Sender: linux-raid-owner@vger.kernel.org To: Peter Grandi Cc: Linux RAID , Linux fs XFS List-Id: linux-raid.ids On Thu, Mar 15, 2012 at 02:07:25PM +0000, Peter Grandi wrote: > >>> I want to create a raid10,n2 using 3 1TB SATA drives. > >>> I want to create an xfs filesystem on top of it. The > >>> filesystem will be used as NFS/Samba storage. > > Consider also an 'o2' layout (it is probably the same thing for a > 3 drive RAID10) or even a RAID5, as 3 drives and this usage seems > one of the few cases where RAID5 may be plausible. Well, for a file server like NFS/Samba, you could also consider raid10,f2. I would think you could get about double the read performance compared to n2 and o2 layouts, and also for individual read transfers on a running system you would get somthing like double the read performance. Write performance could be somewhat slower (0 to 10 %) bot as users are not waiting for writes to complete, they will probably not notice. best regards keld