I guess I have been confused. I did not realize this was a 5 disk RAID5 with 1 spare. Six disks total. Is this correct? If the above is correct, then: Based on Neil's email, I now see that /dev/hdi1 is and was the spare. This is the device that was hot removed. This device should have no data on it. So it should not be included when trying to recover. Just to be safe, do you know the device names of the six devices in the array? If so, try to assemble, but don't include hdi1 or hdk1. If Neil is correct, your 2 failures were only 2 seconds apart. Has your array been down since Sat Sep 25 22:07:26 2004? If so, I guess hdk1 can't be too out of date! So, use it if needed. Neil said to use this command: mdadm -A /dev/md0 --uuid=ec2e64a8:fffd3e41:ffee5518:2f3e858c --force /dev/hd?1 I am worried that it may attempt to use hdi1, which is the spare. Also, I don't know that all of your devices match hd?1. I have never seen the complete list of devices. Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Neil Brown Sent: Sunday, November 14, 2004 6:43 PM To: Robert Osiel Cc: Guy; linux-raid@xxxxxxxxxxxxxxx Subject: Re: A few mdadm questions On Sunday November 14, bob@xxxxxxxxx wrote: > > I'll wait and see if Neil has any advice. *crosses fingers* > Well, my reading of the information you sent (very complete, thanks), is: At Update Time Sat Sep 25 22:07:24 2004 when /dev/hdk1 last had a superblock update, the array have one failed drive (not present) and one spare. At this point it *should* have been rebuilding the spare to replace the missing device, but I cannot tell if it actually was. At Update Time Sat Sep 25 22:07:26 2004 (2 seconds later) when /dev/hdi1 was last written another drive had failed, apparently [major=56, minor=1] which is /dev/hdi1 on my system, but seems to be different for you. If that drive, whichever it is, is really dead, then you have lost all your data. If, however, it was a transient error or even a single-block-error then you can recover most of it with mdadm -A /dev/md0 --uuid=ec2e64a8:fffd3e41:ffee5518:2f3e858c --force /dev/hd?1 This will choose the best 4 drives and assemble a degraded array with them. It will only update the superblocks and assemble the array - it won't touch the data at all. You can then try mounting the filesystem read-only and dumping the data to backup. When you add the 5th drive (hdi?) it should start rebuilding. If it gets a read error on one of the drives, the rebuild will fail, but the data should still be safe. I'm still very surprised that you managed to "raidhotremove" without "raidsetfaulty" first... What kernel (exactly) are you running? NeilBrown - 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 - 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
