One drive in 8 drive disk group with hot spare (9 total) had predictive failure [slot 2]. Wrong drive [slot 0] replaced with new drive. Spare and copy back on [slot 0] successful. Subsequently two drives [0] and [2] removed at same time (don't ask). Two of 3 virtual disks on disk group and disk group failed. Subsequent shell game of disks, but now back to original status before two drives were removed. All physical disks optimal. Disk group and 2/3 virtual disks still failed. Considering revive disk group. Advice? Out of warrany; no support; blah blah blah.