Hi, I had posted to this list a week ago asking for assistance in recovering a filesystem on my RAID5 array. After having recovered what I could (from other sources, backups, etc) I decided to start fresh, and found I have even bigger problems. I zeroed the superblocks on the old array partitions, and removed the partitions and partition tables from the drives, so there shouldn't have been anything lingering that would cause problems. I setup gpt partition tables on the drives, created non-fs partitions on them, created the array, and after it finished rebuilding I created an xfs partition on md0. It worked fine at this point. Then I rebooted and found the array assembled fine, but I could not mount it. I get the error "mount: wrong fs type, bad option, bad superblock on /dev/md0". Specifically, I did the following: # parted /dev/sdb mkpart non-fs 0% 100% # parted /dev/sdc mkpart non-fs 0% 100% # parted /dev/sdd mkpart non-fs 0% 100% # mdadm --create --verbose /dev/md0 --level=5 --chunk=128 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1 After it finished rebuilding, I did: # mdadm --examine --scan >> /etc/mdadm/mdadm.conf Which resulting in the following mdadm.conf: DEVICE partitions CREATE owner=root group=disk mode=0660 auto=yes HOMEHOST <system> MAILADDR root ARRAY /dev/md0 level=raid5 num-devices=3 UUID=78902c67:a59cf188:b43fc0e6:226924cf I then formatted md0 with xfs: # mkfs.xfs /dev/md0 meta-data=/dev/md0 isize=256 agcount=32, agsize=22892768 blks = sectsz=4096 attr=2 data = bsize=4096 blocks=732568576, imaxpct=5 = sunit=32 swidth=64 blks naming =version 2 bsize=4096 log =internal log bsize=4096 blocks=32768, version=2 = sectsz=4096 sunit=1 blks, lazy-count=0 realtime =none extsz=262144 blocks=0, rtextents=0 I mounted md0, used it, did some tests with bonnie++. Everything was working fine. Then I rebooted. The array assembled fine on reboot, but the filesystem was missing or corrupted. I get the following error: # mount -t xfs /dev/md0 /media/archive 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 In /var/log/messages I see: from boot: kernel: md: md0 stopped. kernel: md: bind<sdc1> kernel: md: bind<sdd1> kernel: md: bind<sdb1> kernel: raid5: device sdb1 operational as raid disk 0 kernel: raid5: device sdd1 operational as raid disk 2 kernel: raid5: device sdc1 operational as raid disk 1 kernel: raid5: allocated 3172kB for md0 kernel: raid5: raid level 5 set md0 active with 3 out of 3 devices, algorithm 2 kernel: RAID5 conf printout: kernel: --- rd:3 wd:3 kernel: disk 0, o:1, dev:sdb1 kernel: disk 1, o:1, dev:sdc1 kernel: disk 2, o:1, dev:sdd1 kernel: md0: unknown partition table when attempting to mount: kernel: XFS: bad magic number kernel: XFS: SB validate failed kernel: XFS: bad magic number kernel: XFS: SB validate failed Here is the relevant info to show the array is up and running: # mdadm --detail /dev/md0 /dev/md0: Version : 00.90 Creation Time : Thu Jan 15 21:45:26 2009 Raid Level : raid5 Array Size : 2930276864 (2794.53 GiB 3000.60 GB) Used Dev Size : 1465138432 (1397.26 GiB 1500.30 GB) Raid Devices : 3 Total Devices : 3 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Thu Jan 22 18:22:07 2009 State : clean Active Devices : 3 Working Devices : 3 Failed Devices : 0 Spare Devices : 0 Layout : left-symmetric Chunk Size : 128K UUID : 78902c67:a59cf188:b43fc0e6:226924cf (local to host 4400x2) Events : 0.2 Number Major Minor RaidDevice State 0 8 17 0 active sync /dev/sdb1 1 8 33 1 active sync /dev/sdc1 2 8 49 2 active sync /dev/sdd1 $ cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sdb1[0] sdd1[2] sdc1[1] 2930276864 blocks level 5, 128k chunk, algorithm 2 [3/3] [UUU] unused devices: <none> So, does anyone know what is happening to my filesystem on md0 and how to stop it from happening? Thanks in advance, Mike -- 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