Corrupted backup floppies from cpio

[John Kennedy]

Here's a question concerning Microport Unix (SYS V/AT), and maybe it's a
Unix question in general.

A couple of weeks ago, I backed up everything on my disk for the purpose
of repartitioning between DOS and Unix.  I used a find ... | cpio -ocv >
/dev/rdsk/0s24.  This is the way I had always done backups.  Maybe I
should have used tar or whatever, but that's water over the dam.

When I went to restore the files, with a cpio -icdumv < /dev/rdsk/0s24,
the first few disks read okay, but then the "out of phase. get help"
message appeared.  Apparently the disks were not written correctly.

Going back to the previous backups I had done, I found that many of them,
too, were unreadable.  This leaves me in a pretty sad state.

I am assuming that some sort of header information is trashed, but that there
also could be some good images of some files on the floppies.

I have been to read the disks to a file by using dd, and what I was wondering
if anyone might know, is there some way of modifying that file, and extracting
information about any good files and salvaging some data?

Please email replies to !chinet!johnk.

Thanks.