Originally Posted by
blueball
If I understand properly the bad disk is one of the two in RAID 0. If that is the case you need to backup everything NOW. If you lose that disk you will lose everything on the RAID 0.
If your controller allows you to use two different sized disks as a RAID 1 pair the the 2TB disk will appear as a 250Gb disk wasting a heap of space.
Personally, I would stick the remaining 250Gb disk in a cupboard and run with the single 2TB disk. I doubt you will notice any speed difference.