On 13/09/2014 17:45, Alan McKinnon wrote: <snip>
If I do: fdisk /dev/sda t 1 fd Won't it destroy data on /dev/sda?No.
Although mdadm will. A simple solution is to create the array with only the second disk as the initial member and designate the other device as literally "missing". The array will function in degraded mode. Then it is simply a matter of copying over the data from the original filesystem on the first disk, after which it may be (destructively) added to the array.
--Kerin
