My server just experienced some trauma while moving, and two of my drives are toast.  I happen to have a current dd clone of one of those disks (whew!), but I haven't been able to find a way to convince unRAID that the cloned disk is to be trusted, so the array can start up so I can get the contents off of the other dead drive.  The management interface just says "WRONG DISK".  I can't just run initconfig if I'm still down a drive.

 

Any ideas?

 

unRAID rebuilds the contents of a partition. So, the basic steps are to get the new drive partitioned with a proper unRAID partition and then use the trust my array procedure except specify the disk to rebuild instead of doing a parity check. The partition part can be accomplished by installing it as a single data drive and starting the array (you can even use a temp unlicensed USB stick to do this). I don't know the exact steps for the rest because I have never done it on anything newer then about unRAID 4.6. This is the wiki page.

 

http://lime-technology.com/wiki/index.php/Make_unRAID_Trust_the_Parity_Drive,_Avoid_Rebuilding_Parity_Unnecessarily

 

To rebuild a disk you put the disk number you want to rebuild instead of 99 in the mdmcd command.

 

mdcmd set invalidslot 4 - this would rebuild disk4, but only the partition so you need a proper partition to start.

 

Now, you are introducing an array drive which may not be an exact duplicate of the failed one so the drive being rebuilt based off this drive may not turn out 100%. You may have to run some reiserfsck commands to fix or rebuild it.

 

I don't suppose there's a way to bring up the array in a degraded state, without a replacement for the other dead disk?  I have other drives that I could copy files over to, but not one of the same size.

See here: http://lime-technology.com/forum/index.php?topic=30009.0

I don't believe you can get a valid array again without having a working disk to assign for the missing one.  You could try the steps with an extra drive and then force a failure (unplug the drive) but that is getting into an experimental mode that could easily cause the loss of data. Also, if the cloned drive is not an exact copy of the second failed drive then the file system of the missing simulated drive would have corruption and you wouldn't be able to access the data without first rebuilding.

 

At any rate, the link posted is the steps but I still believe you need to create the partition first since unRAID protects the first (and only) partition on each disk and not the complete contents.

 

FYI, I recently swapped drives and I had to click a button to start rebuilding the data onto the new drive myself once the array was running.