Thank you for the additional insight Neil. If I use partitions for my md members (like /dev/sdd1 and /dev/sdg1), do I run the --zero-superblock on /dev/sdd1 or /dev/sdd for example? Finally, I am using Superblock v1.0 here, but in reviewing the mdadm thread archives, it seems that v1.2 is more commonly recommended. Is there any reason to use one or the other? Thanks! -Thomas On Mon, May 11, 2009 at 7:01 PM, NeilBrown <neilb@xxxxxxx> wrote: > On Tue, May 12, 2009 11:32 am, fibre raid wrote: >> Hi, >> >> I am facing an issue with mdadm on Ubuntu Jaunty 9.04 Server 64-bit >> edition. >> >> Host: >> - Dual quad-core Xeon 5450 3.0 GHz CPUs >> - 16 GB RAM >> - Ubuntu 9.04 server (2.6.28-11) >> - mdadm 2.6.7.1 >> - LSI 3801E controller with 12 x Seagate Cheetah 15K.5 300GB drives >> >> I am trying to create a RAID 0 md device from two of the 15K.5 drives. >> When I boot my Host, it seems like there is some legacy md data in >> /proc/mdstat. However, /etc/mdadm.conf is empty. >> >> root@JAUNTY:~# cat /proc/mdstat >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] >> [raid4] [raid10] >> md_d1 : inactive sdx[1](S) >> 292968640 blocks >> >> md_d0 : inactive sdj[3](S) sdm[0](S) sdf[7](S) sdg[6](S) >> 1171874560 blocks >> >> unused devices: <none> >> > > Presumably all these devices have md superblocks on them > that make them look like part of some old array. > Why jaunty partially assembled them isn't clear. Maybe it > is using --incremental and it is waiting for the rest of the > array to appear. > You can look at each device with --examine. e.g. > mdadm --examine /dev/sdx > > If it reports an array that you don't want to still have, you can > remove the metadata using > mdadm --zero-superblock /dev/sdx > >> >> I proceed to stop and remove these md devices and use /proc/mdstat to >> verify that they were removed. >> >> root@JAUNTY:~# mdadm -S /dev/md_d1 >> mdadm: stopped /dev/md_d1 >> root@JAUNTY:~# mdadm -S /dev/md_d0 >> mdadm: stopped /dev/md_d0 >> root@JAUNTY:~# mdadm -r /dev/md_d1 >> root@JAUNTY:~# mdadm -r /dev/md_d0 > > > These last two commands do nothing. They are asking mdadm to remove > some devices from the arrays /dev/md_d1 and then /dev/md_d0, > but don't list any devices to remove. As the arrays are already > stopped, there is nothing to remove anyway. > > >> root@JAUNTY:~# cat /proc/mdstat >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] >> [raid4] [raid10] >> unused devices: <none> >> >> >> Now it appears that the md devices are removed. > > "stopped" is the term we normally use. > >> >> I then try to create an md device: >> >> root@JAUNTY:~# mdadm -C -f -e 1.0 -R /dev/md0 -l 0 -n 2 -c 64 /dev/sdd >> /dev/sdg >> mdadm: /dev/sdg appears to be part of a raid array: >> level=raid0 devices=8 ctime=Sun Mar 22 23:22:03 2009 >> mdadm: array /dev/md0 started. >> root@JAUNTY:~# cat /proc/mdstat >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] >> [raid4] [raid10] >> md0 : active raid0 sdg[1] sdd[0] >> 585937408 blocks super 1.0 64k chunks >> >> unused devices: <none> >> >> >> Why does mdadm report /dev/sdg as part of a raid array? I removed all >> the md devices as shown above. Thank you for your help! > > Because it still has metadata on it recording the fact that it > was recently part of an array. Creating a new array using that > device will have erased any old metadata. > You can remove the metadata without creating an array by using > --zero-superblock as described above. > > NeilBrown > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
