Hi Neil, thanks a lot, the array is rebuilt and redundant again, apparently with no loss of data (at least all fscks ran without complaints). It took me a while to get to this point, since the dd_rescue randomly failed after an hour or two, so I didn't get to try more than once per night. That seems to be fixed now with a new SATA cable. I just wanted to quickly write down here what the original cause of the problem was, in case someone ever googles this conversation: after mdadm -Af /dev/md0 /dev/sd[bdef]1 fsck -nf /dev/md0 I would get the message that /dev/md0 was busy, even though according to mount it was not mounted anywhere. Trying to mount it would report it as already mounted, but the data was not visible at its usual mountpoint. This was indeed the same symptom I had had in the first place after trying with --re-add and --run. It turns out ubuntu does something odd with mounts that are mentioned in /etc/fstab but are not available at bootime. I did not understand what this actually is, but as a result the device is "in use" even though the data is not visible at the mount point. After I temporarily removed /dev/md0 from /etc/fstab and rebooted I was able to follow your advice to the letter without any more problems, and I strongly suspect my original approach would have worked as well. Again, thank you so much for your help! Cheers, Felix -- 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
