Keep media name, overwrite dump

[Valentijn Sessink <valentyn+xfs@nospam.openoffice.nl>]

Hello list,

I'm using xfsdump for a couple of machines. The thing I never understood is
how exactly the media label is supposed to work. The xfsdump man page says:

   Labels
       The operator can specify a label to identify the dump ses­
       sion and a label to identify a media object. [...]

       The media label is used to identify media objects, and  is
       independent  of the session label.  Each media file on the
       media object contains a copy of the media label.  An error
       is  returned  if the operator specifies a media label that
       does not match the media label on a media object  contain­
       ing  valid  media files.  Media labels are recorded in the
       inventory.

What I would like to do (and what seems sensible to me) is record a media
label, then use those media to make, for example, daily backups. Something
like a Monday, Tuesday etc. tape.

However, if I specify "-o", xfsdump overwrites the tape without looking
(which is documented behaviour, so OK), and without -o it appends to the
media (also documented), whichever media name I specify.

Is there a way to read the media label (to reuse it)? Even better: is there
a way to tell xfsdump to only use media with, let's say, the "TUESDAY"
label, and return an error (as per xfsdump(8)) if another media is in the
streamer? Can xfsdump overwrite an older dump, while keeping the media name?
And, what should I understand from the "An error is returned" remark under
Labels in xfsdump(8)?

V.
-- 
http://www.openoffice.nl/   Open Office - Linux Office Solutions
Valentijn Sessink  valentyn+sessink@nospam.openoffice.nl