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Here's the run down: We have a 2 disk RAID 0 array. One of the drives failed and the other is marked as depreciating. We aquired a new drive, same specs as the old. To our thinking we simply replaced the old drive with the new drive and theh RAID should have taken care of the mirroring all on its own. well, it did not.

Now we are trying to figure out a way to make the new disk a mirrored disk and I had a thought that if we simply copy the whole drive EXACTLY like the other one and put it back into the RAID card we should be good to go.

Well, its not that simple, most copy programs don't do RAID 0 and I don't really trust a whole bunch of non-tested tried and true programs.

I decided to try out Ubuntu LiveCD and dd. I understand how to use dd when we get names like /dev/sda and /dev/sdb, ...

The drives, when I do

sudo lshw -C disk

show up as UNCLAIMED and they have no nifty little name that would have made this so much simpler.

Any suggestions on getting this RAID array back up and running.

We basically have one shot at this, as the other drive is the only copy of the server.

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Could you please describe you RAID configuration in more detail, is it a hardware or a software RAID, what hardware/software? – bender Jan 12 '13 at 0:34

Raid0 = stripe, not mirror. Loss of any disk with raid0 results in loss of the entire array. You will need to restore from backup.

If you really have a raid1, then mdadm --add should be able to add the new drive to the array and it should automatically resync. Do NOT dd the drive.

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