[excuse strange formatting - posting from a new news client] I have a problem trying to replace a failed drive in a RAID1 setup under Debian (woody). Background: I have a 2 disk mirror, RAID 1 setup. It is made up of two 180Gb Western Digital WD1800JB drives. Both are partitioned as: Partition Table for /dev/hda First Last # Type Sector Sector Offset Length Filesystem Type (ID) Flags -- ------- -------- --------- ------ --------- ---------------------- --------- 1 Primary 0 4000184 63 4000185 Linux raid autode (FD) Boot (80) 2 Primary 4000185 5992244 0 1992060 Linux swap (82) None (00) 3 Primary 5992245 351646784 0 345654540 Linux (83) None (00) Partition Table for /dev/hdc First Last # Type Sector Sector Offset Length Filesystem Type (ID) Flags -- ------- -------- --------- ------ --------- ---------------------- --------- 1 Primary 0 4000184 63 4000185 Linux raid autode (FD) Boot (80) 2 Primary 4000185 5992244 0 1992060 Linux swap (82) None (00) 3 Primary 5992245 351646784 0 345654540 Linux (83) None (00) Output of /proc/mdstat (when both devices are running): Personalities : [linear] [raid0] [raid1] read_ahead 1024 sectors md1 : active raid1 hdc3[1] hda3[0] 172827200 blocks [2/2] [UU] md0 : active raid1 hdc1[1] hda1[0] 1999936 blocks [2/2] [UU] unused devices: <none> Both raid devices have ext3 filesystems on them. The problem: hda has now failed, and I have tried to put in a new drive. However, when the failed drive is replaced with the new drive, the raid device md1 will not restart and produces the following errors: Feb 12 14:09:59 bart kernel: md: invalid raid superblock magic on hda3 Feb 12 14:09:59 bart kernel: md: hda3 has invalid sb, not importing! Feb 12 14:09:59 bart kernel: md: could not import hda3! Feb 12 14:09:59 bart kernel: md: autostart hda3 failed! Feb 12 14:09:59 bart kernel: EXT3-fs: unable to read superblock whereas, the md0 device auto-recovers - presumably because the auto-detect flag is set and the kernel is dealing with the rebuild: Feb 12 14:09:59 bart kernel: md: linear personality registered as nr 1 Feb 12 14:09:59 bart kernel: md: raid0 personality registered as nr 2 Feb 12 14:09:59 bart kernel: md: raid1 personality registered as nr 3 Feb 12 14:09:59 bart kernel: md: md driver 0.90.0 MAX_MD_DEVS=256, MD_SB_DISKS=27 Feb 12 14:09:59 bart kernel: md: Autodetecting RAID arrays. Feb 12 14:09:59 bart kernel: [events: 00000000] Feb 12 14:09:59 bart kernel: md: invalid raid superblock magic on hda1 Feb 12 14:09:59 bart kernel: md: hda1 has invalid sb, not importing! Feb 12 14:09:59 bart kernel: md: could not import hda1! Feb 12 14:09:59 bart kernel: [events: 000000ce] Feb 12 14:09:59 bart kernel: md: autorun ... Feb 12 14:09:59 bart kernel: md: considering hdc1 ... Feb 12 14:09:59 bart kernel: md: adding hdc1 ... Feb 12 14:09:59 bart kernel: md: created md0 Feb 12 14:09:59 bart kernel: md: bind<hdc1,1> Feb 12 14:09:59 bart kernel: md: running: <hdc1> Feb 12 14:09:59 bart kernel: md: hdc1's event counter: 000000ce Feb 12 14:09:59 bart kernel: md0: removing former faulty hda1! Feb 12 14:09:59 bart kernel: md: md0: raid array is not clean -- starting background reconstruction Feb 12 14:09:59 bart kernel: md: RAID level 1 does not need chunksize! Continuing anyway. Feb 12 14:09:59 bart kernel: md0: max total readahead window set to 124k Feb 12 14:09:59 bart kernel: md0: 1 data-disks, max readahead per data-disk: 124k Feb 12 14:09:59 bart kernel: raid1: device hdc1 operational as mirror 1 Feb 12 14:09:59 bart kernel: raid1: md0, not all disks are operational -- trying to recover array Feb 12 14:09:59 bart kernel: raid1: raid set md0 active with 1 out of 2 mirrors Feb 12 14:09:59 bart kernel: md: updating md0 RAID superblock on device Feb 12 14:09:59 bart kernel: md: hdc1 [events: 000000cf]<6>(write) hdc1's sb offset: 1999936 Feb 12 14:09:59 bart kernel: md: recovery thread got woken up ... Feb 12 14:09:59 bart kernel: md0: no spare disk to reconstruct array! -- continuing in degraded mode Feb 12 14:09:59 bart kernel: md: recovery thread finished ... Feb 12 14:09:59 bart kernel: md: ... autorun DONE. >From everything I have read, all I should have to do is replace the drive when it fails with a correctly partitioned spare, reboot. Wait for the raid to autostart (in degraded mode) and raidhotadd the partitions back in to get them resynced. Is this correct? If not, where am I going wrong? Thanks Marcus -- Marcus Williams - http://www.onq2.com Quintic Ltd, 39 Newnham Road, Cambridge, UK -- Composed with Newz Crawler 1.3 http://www.newzcrawler.com/ - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html