I apologize for being so verbose in my last post...it was late. My problem again, in a more succinct form: After a system crash during bootup, I attempted: > mdadm --add /dev/md0 /dev/sdb3 This caused the following: Number Major Minor RaidDevice State 0 8 51 0 active sync /dev/sdd3 1 8 35 1 active sync /dev/sdc3 2 0 0 - removed 3 0 0 - removed 4 8 19 - spare /dev/sdb3 5 8 3 - faulty /dev/sda3 I then did: >mdadm --assemble --force /dev/md0 Which gave me: Number Major Minor RaidDevice State 0 8 51 0 active sync /dev/sdd3 1 8 35 1 active sync /dev/sdc3 0 0 0 0 removed 3 8 3 3 active sync /dev/sda3 Which generates errors when I try and copy off large amounts of data: About ten of these: ata1: translated ATA stat/err 0x25/00 to SCSI SK/ASC/ASCQ 0x4/00/00 ata1: status=0x25 { DeviceFault CorrectedError Error } SCSI error : <0 0 0 0> return code = 0x8000002 sda: Current: sense key: Hardware Error Additional sense: No additional sense information end_request: I/O error, dev sda, sector 489794513 And a ton of these: EXT3-fs error (device md0): ext3_get_inode_loc: unable to read inode block - inode=229379, block=458799 Yet fsck reports clean: > fsck -n /dev/md0 fsck 1.38 (30-Jun-2005) e2fsck 1.38 (30-Jun-2005) /: clean, 514472/90718208 files, 114796878/181417968 blocks Should I do this: > fsck -n -c /dev/md0 > mdadm --assemble /dev/md0 > mdadm --add /dev/md0 /dev/sdb3 or this: > mdadm -c /dev/md0 -l 5 -n 4 -x 0 -f /dev/sdd3 /dev/sdc3 /dev/sdb3 /dev/sda3 > mdadm -S /dev/md0 > mdadm --assemble --update=resync /dev/md0 or ??? If anyone has this knowledge, please share. I'm in over my head on this one. Thanks in advance! P.S. I am currently running a non-distructive badblock check while I wait for expert advice: > fsck -n -c -c /dev/md0 fsck 1.38 (30-Jun-2005) e2fsck 1.38 (30-Jun-2005) Checking for bad blocks (non-destructive read-write test) Testing with random pattern: 4964224/ 181417968 - 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