Chris Eddington wrote:

Key questions:
- I assume ddrescue will do a much better job of correcting errors when
imaging a disk?  My colleague used ghost which is just a copy tool.  I
don't understand the capabilities of ddrescue on raid partitions that well.

ddrescue should do a *much* better job.
It knows nothing about raid and operates on the underlying device. It retries
bad sectors in a clever manner.

- fdisk -l reports that all the drives are exactly the same size with
exactly the same # sectors shown below.  I don't quite follow the
hpa_resize issue, but it appears the drives don't have hidden HPA
sectors - I guess?  Note that sdc is the original drive, where sda, sdb,
and sdd are the imaged drives.

So what do you recommend to do first?  Should I try xfs_repair on the
ghost copy,

No
 or just re-copy myself using ddrescue?
Yes.
  Are there special

settings to ddrescue I should consider to verify/correct potential HPA
changes?

Ideally just ddrescue the entire device to a file and use loopback.

For the faulty disk then if you have space, make a second copy and xfs_repair
using that. If it fails then you can easily re-image the good disks but it may
not be so easy to re-image the bad one.

David