From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tyler Subject: Re: BUGREPORT: mdadm v2.0-devel - Examine and zero-superblock misbehaving Date: Tue, 03 May 2005 16:55:32 -0700 Message-ID: <42780F74.8050900@dtbb.net> References: <42775A61.6020708@dtbb.net> <17016.3630.940288.540120@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: <17016.3630.940288.540120@cse.unsw.edu.au> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Neil, I tried removing the superblock several times to test the theory, but it seems the removal isn't working.. maybe because of the semi-invalid information of 380 spare drives? I'm not sure? root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc /dev/hdc: Magic : a92b4efc Version : 01.00 Array UUID : f4b2dc026e:a3cc3e95:de0563f5:199250 Name : Creation Time : Tue May 3 11:16:22 2005 Raid Level : raid5 Raid Devices : 3 Device Size : 390721952 (186.31 GiB 200.05 GB) Super Offset : 390721952 sectors State : active Device UUID : f4b2dc026e:a3cc3e95:de0563f5:199250 Update Time : Tue May 3 11:16:22 2005 Checksum : d4cd5d80 - correct Events : 0 Layout : -unknown- Chunk Size : 64K Array State : Uuu 381 spares root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdd root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdd mdadm: Unrecognised md component device - /dev/hdd Neil Brown wrote: >On Tuesday May 3, pml@dtbb.net wrote: > > >>On a site note, mdadm --zero-superblock doesn't seem to work correctly >>with mdadm v2.0-devel, it reports no error when you use it, but you can >>mdadm -E /dev/hdX after using it, and there is still a superblock, if >>you use mdadm v1.9.0-2, it works correctly, and the examine shows >>nothing afterwards. Examples follow after the first problem. Mdadm >>v2.0 also seems to misreport the findings using the examine function.. >>"381 spares." Using kernel 2.6.12-rc3-mm2. >> >>First i run zero superblock with mdadm v2.0-devel from current dir: >> >>root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc >> >>Then examine the superblock using mdadm v2.0-devel from current dir: >> >>root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc >>/dev/hdc: >> Magic : a92b4efc >> Version : 01.00 >> >> > >What has happened here is that "mdadm --zero-superblock" found a >version 0.90 superblock and zeroed it. There was still a version 1 >superblock (which lives in a different location). and -E found that. >If you run --zero-superblock serveral times it should zero everything, >though normally you would not expect to have multiple superblocks. > > > >> Array State : Uuu 381 spares >> >> >> > >Not sure about this. I'll have to spend a while reminding my self >what is meant to happen, and what actually does... > >NeilBrown > > > >