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Have anyone tried to add a newly bought drive with an already running drive to create RAID 1 using software RAID (Supermicro) without data loss? Is it possible?
Any answer is highly appreciated!
I don't know if you can convert a drive in place, but otherwise:
Take a backup!
Create a new RAID-1 array with the new drive. It'll start in degraded mode because it's "missing" a drive.
Copy everything from old to new
Nuke old and pretend it's a replacement for the "failed drive" in the RAID-1 array, attach it, and let it sync up