Why does ontape dislike norewind devices?
On 11th Jun 1998 davek@summitdata.com (David Kosenko) wrote:- It is primarily an issue with multiple-volume backups, and with restores. When ontape switches to writing the second volume of an archive set, it first reads the header from the tape to be sure that the tape was actually switched (i.e. it won’t write the second volume over the first volume), then “rewinds” the tape. It does the “rewind” by closing the device, which, on a normal (i.e. not no-rewind) driver will cause the tape to rewind. If you use a norewind driver in this case, ontape will read a bit of the tape, corresponding to the header it would write. It would then close the device, reopen it and start writing the new header. With the norewind driver, that header would be one header’s worth into the tape, rather than at the start. If you tried to restore from that tape, the restore would fail. I don’t recall offhand if the norewind is an issue with the first tape in a volume or not. It’s been a while since I dove into t
