On Thursday March 20, lists@schlich.org wrote: > > And when I try to mount the array: > --8<-- > EXT3-fs error (device md(9,1)): ext3_check_descriptors: Block bitmap for group 509 not in group (block 4294967295)! > EXT3-fs: group descriptors corrupted ! > --8<-- > > What should I do now? Raidhotadd the 4th device? Run e2fsck prior to > that or afterwards? I would fsck -n /dev/md1 to non-distructively see how much damage there is. If that shows an uncomfortable large amount of damage, you could assembling the array from a different triple of devices. It is currently assemble from /dev/hd[gki]1 If you want to try g, k and e for example, use mdadm -Af /dev/md1 /dev/hd[gke]1 and then try "fsck -n" on that. I wouldn't hot-add the fourth drive until you have decided you will live with whatever you have. NeilBrown - 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