[NTLUG:Discuss] backing up in linux....

[Robert Pearson]

On 9/15/06, Chris Cox <cjcox at acm.org> wrote:
> Eric Waguespack wrote:
> > thanks for all of the advise... but nothing suggested is really what I
> > was looking for.
> >
> > maybe I'll submit an enhancement request:
> >
> > man cp
> > ..
> > --pause-and-ask-user-for-another-destination-if-target-device-is-full
> > ..
>
> GNU tar will do this... take a look at the man page.
>
> You can call a script when you reach end of medium and do
> whatever you want.


This is not a trivial problem.
What you may be looking for is "multi-volume" capability.
The key phrase is "multi-volume".
Anything that wrote to tape in a serious fashion, backups are serious,
will do multi-volume to most media. You would need to check with the
product vendor to see if it has been tested with USB thumb drives.

The challenge here is not in the software but whether the USB thumb
drives report, or signal, being "full" in a way that the multi-volume
software can get the signal. The early 8 mm cartridge tapes did not
have an EOT (end of tape) sensor, so no EOT signal came from the
drive. You had to calculate bytes written and tape used.

Floppies had the same problem. How does the floppy tell you it is full?
I can remember sitting there with a handful of floppies wanting for the
screen to tell me to insert the next one.
I think I was using the Norton System software.

GNU tar options from "info tar":

`--multi-volume'
`-M'
     Informs `tar' that it should create or otherwise operate on a
     multi-volume `tar' archive.

`--new-volume-script'
     (see -info-script)

`--info-script=SCRIPT-FILE'
`--new-volume-script=SCRIPT-FILE'
`-F SCRIPT-FILE'
     When `tar' is performing multi-tape backups, SCRIPT-FILE is run at
     the end of each tape.  If SCRIPT-FILE exits with nonzero status,
     `tar' fails immediately.