Actually,
I've never needed to try this - but is it reasonable to expect a
"modern" system to be able to archive (using dd) a SCSI drive that's been
formatted to something other than a 512 byte block size?
I think it is. Modern systems will be the ones that have mass storage systems
and networks capable of dealing with disc dumps.
When I've done this, though, I've written my own disc dumping code using SCSI
command blocks to the low-level interface.
yes, I found linux to be incapable of dealing with scsi disks formatted
to non-512 byte multiple blocks...
you end up having to write your own code or hack the o/s to deal with it.
-brad