Received: with ECARTIS (v1.0.0; list xfs); Mon, 18 Sep 2006 08:34:30 -0700 (PDT) Received: from limpet.umeoce.maine.edu (limpet.umeoce.maine.edu [130.111.192.115]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id k8IFYHZd028047 for ; Mon, 18 Sep 2006 08:34:18 -0700 Received: from localhost (cousins@localhost) by limpet.umeoce.maine.edu (8.9.3/8.9.3) with ESMTP id LAA01511; Mon, 18 Sep 2006 11:33:34 -0400 Date: Mon, 18 Sep 2006 11:33:34 -0400 (EDT) From: Steve Cousins Reply-To: cousins@umit.maine.edu To: Shailendra Tripathi cc: "xfs@oss.sgi.com" Subject: Re: swidth with mdadm and RAID6 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-archive-position: 9003 X-ecartis-version: Ecartis v1.0.0 Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com X-original-sender: cousins@limpet.umeoce.maine.edu Precedence: bulk X-list: xfs Content-Length: 3496 Lines: 125 Hi Shailendra, Here is the info: 1. [root@juno ~]# cat /proc/mdstat Personalities : [raid6] md0 : active raid6 sdb[0] sdl[10](S) sdk[9] sdj[8] sdi[7] sdh[6] sdg[5] sdf[4] sde[3] sdd[2] sdc[1] 3907091968 blocks level 6, 64k chunk, algorithm 2 [10/10] [UUUUUUUUUU] unused devices: 2. mdadm --create /dev/md0 --chunk=64 --level=6 --raid-devices=10 --spare-devices=1 /dev/sd[bcdefghijkl] 3. [root@juno ~]# xfs_db -r /dev/md* xfs_db> sb xfs_db> p magicnum = 0x58465342 blocksize = 4096 dblocks = 976772992 rblocks = 0 rextents = 0 uuid = 04b32cce-ed38-496f-811f-2ccd51450bf4 logstart = 536870919 rootino = 256 rbmino = 257 rsumino = 258 rextsize = 144 agblocks = 30524160 agcount = 32 rbmblocks = 0 logblocks = 32768 versionnum = 0x3d84 sectsize = 4096 inodesize = 256 inopblock = 16 fname = "\000\000\000\000\000\000\000\000\000\000\000\000" blocklog = 12 sectlog = 12 inodelog = 8 inopblog = 4 agblklog = 25 rextslog = 0 inprogress = 0 imax_pct = 25 icount = 36864 ifree = 362 fdblocks = 669630878 frextents = 0 uquotino = 0 gquotino = 0 qflags = 0 flags = 0 shared_vn = 0 inoalignmt = 2 unit = 16 width = 144 dirblklog = 0 logsectlog = 12 logsectsize = 4096 logsunit = 4096 features2 = 0 xfs_db> Thanks for the help. Steve ______________________________________________________________________ Steve Cousins, Ocean Modeling Group Email: cousins@umit.maine.edu Marine Sciences, 452 Aubert Hall http://rocky.umeoce.maine.edu Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302 On Mon, 18 Sep 2006, Shailendra Tripathi wrote: > Can you list the output of > 1. cat /proc/mdstat > 2. the command to create 8+2 RAID6 with one spare ? > 3. and output of following: > xfs_db -r /dev/md* > xfs_db> sb > xfs_db> p > > -shailendra > > Steve Cousins wrote: > >> I have a RAID6 array of 11 500 GB drives using mdadm. There is one > >> hot-spare so the number of data drives is 8. I used mkfs.xfs with > >> defaults to create the file system and it seemed to pick up the chunk size > >> I used correctly (64K) but I think it got the swidth wrong. Here is what > >> xfs_info says: > >> > >> =========================================================================== > >> meta-data=/dev/md0 isize=256 agcount=32, agsize=30524160 > >> blks > >> = sectsz=4096 attr=0 > >> data = bsize=4096 blocks=976772992, imaxpct=25 > >> = sunit=16 swidth=144 blks, unwritten=1 > >> naming =version 2 bsize=4096 > >> log =internal bsize=4096 blocks=32768, version=2 > >> = sectsz=4096 sunit=1 blks > >> realtime =none extsz=589824 blocks=0, rtextents=0 > >> =========================================================================== > >> > >> So, sunit*bsize=64K, but swidth=144 and swidth/sunit=9 so it looks like it > >> thought there were 9 data drives instead of 8. > >> > >> Am I diagnosing this correctly? Should I recreate the array and > >> explicitly set sunit=16 and swidth=128? > >> > >> Thanks for your help. > >> > >> Steve > >> ______________________________________________________________________ > >> Steve Cousins, Ocean Modeling Group Email: cousins@umit.maine.edu > >> Marine Sciences, 452 Aubert Hall http://rocky.umeoce.maine.edu > >> Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302 > >> > >> > > >