Re: Problem recovering a failed RIAD5 array with 4-drives. --RESOLVED

From: David Greaves
Date: Mon Jul 16 2007 - 11:05:07 EST


James wrote:
I don't know the original order of the array before all the problems
started.
Is there a way to determine the original order?
No, unless you have some old kernel logs of the last time it assembled
the array properly.
The one thing that "--create" does destroy is the information about
any previous array that the drives were a part of.

The order that --detail is showing now is the order that appeared after issuing the command is it is in the email. (ie: a b c d)
Odd. I cannot reproduce it.
I suggest you try different arrangements (of the 3 good drives and the
word 'missing') until you find one that 'fsck -n' likes.

NeilBrown



I don't understand how the order of --detail was different than the command line on my system, however....

YOU ARE A LIFE SAVER!!!

After going through 21 combinations, beginning to lose all hope and plummeting into eternal despair, combo 22 worked. The array is up and working. All the data (1.3Tb) is there and I'm probably the happiest character on the mail list today.

Thanks a bunch for your help.

Funnily enough someone else was having a similar problem on the linux-raid list at the same time

Here's a script that may be useful to others in this predicament - a hell of a lot quicker than doing it by hand...

The 'is the filesystem safe' test probably wants improving from a read-only mount...

http://linux-raid.osdl.org/index.php/RAID_Recovery
http://linux-raid.osdl.org/index.php/Permute_array.pl

David
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