From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nigel J. Terry" Subject: Re: Raid5 reshape Date: Mon, 19 Jun 2006 17:42:41 -0400 Message-ID: <44971A51.6050008@nigelterry.net> References: <449250ED.7090302@irule.net> <17554.21119.487820.638171@cse.unsw.edu.au> <4492D5B1.60004@nigelterry.net> <4492D8D9.7010101@irule.net> <17555.12441.42212.93049@cse.unsw.edu.au> <4493330E.30501@nigelterry.net> <17555.13409.834439.80361@cse.unsw.edu.au> <44945643.3070300@nigelterry.net> <17556.31295.280083.533342@cse.unsw.edu.au> <44947BCA.9040305@nigelterry.net> <44947C98.6060809@nigelterry.net> <17556.32630.611922.294047@cse.unsw.edu.au> <44948002.3050706@nigelterry.net> <44954DB7.2000305@nigelterry.net> <17558.1521.522659.91428@cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17558.1521.522659.91428@cse.unsw.edu.au> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown , linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown wrote: > On Sunday June 18, nigel@nigelterry.net wrote: > >> This from dmesg might help diagnose the problem: >> >> > > Yes, that helps a lot, thanks. > > The problem is that the reshape thread is restarting before the array > is fully set-up, so it ends up dereferencing a NULL pointer. > > This patch should fix it. > In fact, there is a small chance that next time you boot it will work > without this patch, but the patch makes it more reliable. > > There definitely should be no data-loss due to this bug. > > Thanks, > NeilBrown > > Neil That seems to have fixed it. The reshape is now progressing and there are no apparent errors in dmesg. Details below. I'll send another confirmation tomorrow when hopefully it has finished :-) Many thanks for a great product and great support. Nigel [root@homepc ~]# cat /proc/mdstat Personalities : [raid5] [raid4] md0 : active raid5 sdb1[1] sda1[0] hdc1[4](S) hdb1[2] 490223104 blocks super 0.91 level 5, 128k chunk, algorithm 2 [4/3] [UUU_] [=>...................] reshape = 7.9% (19588744/245111552) finish=6.4min speed=578718K/sec unused devices: [root@homepc ~]# mdadm --detail /dev/md0 /dev/md0: Version : 00.91.03 Creation Time : Tue Apr 18 17:44:34 2006 Raid Level : raid5 Array Size : 490223104 (467.51 GiB 501.99 GB) Device Size : 245111552 (233.76 GiB 250.99 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Mon Jun 19 17:38:42 2006 State : clean, degraded, recovering Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 128K Reshape Status : 8% complete Delta Devices : 1, (3->4) UUID : 50e3173e:b5d2bdb6:7db3576b:644409bb Events : 0.3287189 Number Major Minor RaidDevice State 0 8 1 0 active sync /dev/sda1 1 8 17 1 active sync /dev/sdb1 2 3 65 2 active sync /dev/hdb1 3 0 0 3 removed 4 22 1 - spare /dev/hdc1 [root@homepc ~]#