I am trying to get a Pegasus2 R4 working for somebody who uses a Mac (High Sierra). The Pegasus2 was set up for RAID5. It no longer mounts on the Mac. Disk Utility can see the hardware but will not mount the encrypted share containing the user's files. When I try to do this with diskutil and friends, a message from the Promise Utility immediately pops up reporting of a minor error -- that there is a bad sector.

It turns out that there are bad sectors on three of the four installed hard drives.

My questions:

- Say I attempt to put in new drives and rebuild the array (one drive at a time). Will the rebuild fail because the other drives have bad sectors? If so, can I work around this?

- Say I attempt to put in a new drive and rebuild, but the rebuild fails. Can I back out and put the original drive back in? Or will I be stuck and left with a destroyed RAID array?

- Is there any known workaround for mounting the drive despite the bad sectors? Mac OS won't mount the drive because it says "The disk you inserted wasn't readable by this computer".


Naturally, these drives contain Very Important Data that the user cannot afford to lose. Naturally, the user has never backed up this data. So I am trying to tread as carefully as I can.