From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rabbitson Subject: Re: XFS sunit/swidth for raid10 Date: Fri, 23 Mar 2007 09:20:32 +0100 Message-ID: <46038DD0.1060803@rabbit.us> References: <4601BE85.8050005@rabbit.us> <460270F4.1080604@rabbit.us> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids dean gaudet wrote: > On Thu, 22 Mar 2007, Peter Rabbitson wrote: > >> dean gaudet wrote: >>> On Thu, 22 Mar 2007, Peter Rabbitson wrote: >>> >>>> Hi, >>>> How does one determine the XFS sunit and swidth sizes for a software >>>> raid10 >>>> with 3 copies? >>> mkfs.xfs uses the GET_ARRAY_INFO ioctl to get the data it needs from >>> software raid and select an appropriate sunit/swidth... >>> >>> although i'm not sure i agree entirely with its choice for raid10: >> So do I, especially as it makes no checks for the amount of copies (3 in my >> case, not 2). >> >>> it probably doesn't matter. >> This was essentially my question. For an array -pf3 -c1024 I get swidth = 4 * >> sunit = 4MiB. Is it about right and does it matter at all? > > how many drives? > Sorry. 4 drives, 3 far copies (so any 2 drives can fail), 1M chunk.