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
