Hi, I have a server with 4 HDs: - a 20GB holding a fedora 7 installation; - 3 160GB forming a RAID 5 3 disk array. The first, 20GB HD went south the other day, so I replaced it with another 20GB HD with a fedora 8 installation and tried to mount the RAID array. I get the following error: [root@Fileserver log]# mount /dev/md0 /files mount: wrong fs type, bad option, bad superblock on /dev/md0, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so [root@Fileserver log]# dmesg | tail EXT3-fs error (device md0): ext3_check_descriptors: Block bitmap for group 1920 not in group (block 32800)! EXT3-fs: group descriptors corrupted! everything with the array itself seems to be ok: [root@Fileserver log]# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sdb1[0] sdd1[2] sdc1[1] 320159104 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU] unused devices: <none> [root@Fileserver log]# mdadm --examine /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sdb1: Magic : a92b4efc Version : 00.90.00 UUID : c8aac6bd:221f01ad:3a41d058:d5801b62 Creation Time : Fri Jul 4 09:45:44 2008 Raid Level : raid5 Used Dev Size : 160079552 (152.66 GiB 163.92 GB) Array Size : 320159104 (305.33 GiB 327.84 GB) Raid Devices : 3 Total Devices : 3 Preferred Minor : 0 Update Time : Fri Jul 4 15:17:05 2008 State : clean Active Devices : 3 Working Devices : 3 Failed Devices : 0 Spare Devices : 0 Checksum : 3e1eb720 - correct Events : 0.2 Layout : left-symmetric Chunk Size : 64K Number Major Minor RaidDevice State this 0 8 17 0 active sync /dev/sdb1 0 0 8 17 0 active sync /dev/sdb1 1 1 8 33 1 active sync /dev/sdc1 2 2 8 49 2 active sync /dev/sdd1 /dev/sdc1: Magic : a92b4efc Version : 00.90.00 UUID : c8aac6bd:221f01ad:3a41d058:d5801b62 Creation Time : Fri Jul 4 09:45:44 2008 Raid Level : raid5 Used Dev Size : 160079552 (152.66 GiB 163.92 GB) Array Size : 320159104 (305.33 GiB 327.84 GB) Raid Devices : 3 Total Devices : 3 Preferred Minor : 0 Update Time : Fri Jul 4 15:17:05 2008 State : clean Active Devices : 3 Working Devices : 3 Failed Devices : 0 Spare Devices : 0 Checksum : 3e1eb732 - correct Events : 0.2 Layout : left-symmetric Chunk Size : 64K Number Major Minor RaidDevice State this 1 8 33 1 active sync /dev/sdc1 0 0 8 17 0 active sync /dev/sdb1 1 1 8 33 1 active sync /dev/sdc1 2 2 8 49 2 active sync /dev/sdd1 /dev/sdd1: Magic : a92b4efc Version : 00.90.00 UUID : c8aac6bd:221f01ad:3a41d058:d5801b62 Creation Time : Fri Jul 4 09:45:44 2008 Raid Level : raid5 Used Dev Size : 160079552 (152.66 GiB 163.92 GB) Array Size : 320159104 (305.33 GiB 327.84 GB) Raid Devices : 3 Total Devices : 3 Preferred Minor : 0 Update Time : Fri Jul 4 15:17:05 2008 State : clean Active Devices : 3 Working Devices : 3 Failed Devices : 0 Spare Devices : 0 Checksum : 3e1eb744 - correct Events : 0.2 Layout : left-symmetric Chunk Size : 64K Number Major Minor RaidDevice State this 2 8 49 2 active sync /dev/sdd1 0 0 8 17 0 active sync /dev/sdb1 1 1 8 33 1 active sync /dev/sdc1 2 2 8 49 2 active sync /dev/sdd1 but not with the file system: [root@Fileserver log]# fsck -n /dev/md0 fsck 1.40.4 (31-Dec-2007) e2fsck 1.40.4 (31-Dec-2007) fsck.ext3: Group descriptors look bad... trying backup blocks... fsck.ext3: Bad magic number in super-block while trying to open /dev/md0 The superblock could not be read or does not describe a correct ext2 filesystem. If the device is valid and it really contains an ext2 filesystem (and not swap or ufs or something else), then the superblock is corrupt, and you might try running e2fsck with an alternate superblock: e2fsck -b 8193 <device> [root@Fileserver log]# mke2fs -n /dev/md0 mke2fs 1.40.4 (31-Dec-2007) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 40026112 inodes, 80039776 blocks 4001988 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=0 2443 block groups 32768 blocks per group, 32768 fragments per group 16384 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968 I'm hoping you guys can save my day, because I'm way out of my league, here... TIA, Gustavo Melo -- 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