Hello, while manually failing devices and watching the resync of raid1 md devices on our SAN (IBM DS4700) I've encountered a weird problem: I'm running Debian Etch (kernel 2.6.18-4-xen-amd64, mdadm-2.5.6) I've created a md raid1 device with (mdadm-2.5.6): mdadm --create /dev/md0 --level 1 --name=test-xm36 \ --metadata=1.2 \ --raid-devices=2 \ /dev/disk/by-id/scsi-3600a0b800026c162000006be46b81a74 \ /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 assembling, failing, resyncing works like a charm mdadm --stop /dev/md0 mdadm --assemble --auto=md /dev/md/test-xm36 \ /dev/disk/by-id/scsi-3600a0b800026c162000006be46b81a74 \ /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 mdadm --fail /dev/md/test-xm36 \ /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 mdadm --stop /dev/md/test-xm36 mdadm --assemble --auto=md /dev/md/test-xm36 ... mdadm --add /dev/md/test-xm36 \ /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 /dev/md/test-xm36 gets resynced now without any problems After installing a backported mdadm-2.6.2 (from Debian unstable) and running the same --fail --stop --assemble and --add commands on this md raid1 device (but no --create) the re-adding of the device: mdadm --add /dev/md/test-xm36 \ /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 fails with: mdadm: add new device failed for /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 as 2: Invalid argument and dmesg says: md: sdv has invalid sb, not importing! md: md_import_device returned -22 (/dev/sdv is /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0) Even a mdadm --zero-superblock \ /dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 or dd bs=1k if=/dev/zero \ of=/dev/disk/by-id/scsi-3600a0b80002904d80000197946b818f0 or rebooting does help ?? I'm not able to re-add the failed device with mdadm-2.6.2 ! Adding always fails with the above message. Downgrading to mdadm-2.5.6 cures the problem. After recreating the raid1 device with mdadm-2.6.2 the problem also vanishes. It seems mdadm-2.6.2 has problems re-adding failed devices, when the array was created with mdadm-2.5.6 This could be a major problem when people are upgrading to Debian Etch+1 and can not resync failed raid1 devices they have created with Etch mdadm-2.5.6 Please help, Gerald - 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
