[Techtalk] Detect if Dump used multiple tapes for backup.

Little Girl littlergirl at gmail.com
Tue Jun 22 12:03:22 UTC 2010

Hey there,

Conor Daly wrote:

> I'm backing up a 300Gb filesystem to an SDLT320 tape and,
> occasionally, the weekly level 0 dump will overflow to a second
> tape.
> The same tape is used for a daily level 1 backup using:
> mt -f /dev/nst0 eod
> to wind to the end of data first.
> I'm trying to figure out if there is a way to detect from the first
> tape if the backup overflowed to a second tape so that I can load
> the second tape before doing the 'mt eod' bit.  Obviously I cannot
> ask the dump at the start of the tape if it overflowed as it will
> not know at that point.
> The tapes are re-used on a 3-monthly basis so it is always possible
> that the second tape may have a partial dump already on it so I
> cannot directly ask that.
> If I do a
> mt -f /dev/nst0 eod
> followed by a
> mt -f /dev/nst0 status
> I get flags:
> both in the case of a full tape and in the case of a part-full tape.
> Any thoughts?

I'm not sure if this will be of any use to you, but I've attached a
small Bash script that checks the size of a directory (in KB) and
displays the results (also ringing the system bell for undesired
results). Maybe you could add something like this into the mix.

I got the 12 KB by emptying the target directory. Different
directories are different sizes when empty (no idea why), so you'll
want to adjust that number to whatever size the directory is when
you're happy with it.

I don't have any magnetic tapes, so I don't know if regular
scripts will even work on them. If this is totally off base,
please ignore. (:

Little Girl

There is no spoon.

More information about the Techtalk mailing list