Multiple tape backups with cpio

[John G. DeArmond]

aab at cichlid.com (Andrew A. Burgess) writes:

>I use SCO UNIX 3.2 and on this system the way this works is that cpio
>simply counts the bytes and then prompts you for a new tape when the
>count reaches the tape size (the tape size is explicitly set by parameters
>to cpio). No end of tape indication from the tape is required.
>If ISC does not work this way you should be able to insert
>a program into the pipeline (between cpio and the tape) that does this counting
>and prompts you to change tapes. Similarly when restoring, cpio wouldn't
>know the difference.

>Anyone see any problems with this?

>Andy


Yeah, it's way too complicated.  KISS. :-)  Cpio is SUPPOSED to detect end
of file and prompt you for a new tape.  Says so right in TFM.  At least
under ISC 2.0.2 and 2.2, it does not work. (experience with 4 systems so 
far in that regard.)  

The final solution is to get a copy of AFIO - available from comp.unix.sources
archives or I'll even mail copies as long as the requests don't get too
heavy).  This is a PD replacement for cpio that adds a number of new 
enhancements.  One of these is the ability to specify the size of each
device with a command line option.  I've added some enhancements such
as the ability to specify different devices when prompted for the next
"tape".  This allows one to recover gracefully when, for example, a 
backup fails in the middle of the 5th tape.  (just restart and send the
output to /dev/null and specify the tape drive when it prompts for the 5th
tape.)  Another benefit is that it is several times faster than cpio.

Afio has a few warts but it is vastly better than the stock cpio.  Highly
recommended.

John

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