> Hi,
> 
> I think I've seen this one mentioned before, but if you have an LTO
> Ultrium tape that was previously labeled with NetWorker, and there's
> like 80 GB of data on it from one or more NetWorker backups (tape is say
> 40% full), and someone accidentally runs 'mt -f device rewind' and then
> tars like 220 MB of data to it using tar, are you SOL, or can any of the
> savesets that reside on the portion of the tape that was not affected
> still be recovered? Clearly, most of the data would not have been
> affected, but if the tape was rewound and tar was run then I'm guessing
> the NetWorker label would most likely have been overwritten and it would
> not be possible, therefore, to mount the tape, but rather than deleting
> the volume and re-labeling the tape, might there be a way to rescue the
> data off there? Any thoughts?


The problem is not that much Networker in this case....
Actually the Networker tape format enables Networker to figure out
what is on the tape.
But the problem is the tape drive and it's firmware. 
When you write the tar-stuff on the tape you will generate an
Logical EndOfTape mark (actually two consequtive  EOF:s)
after the data and no unmodified tape drive will move the tape beyond
this mark.

There are companies that specialize in recovering such tapes by using
modified tape drives, but their services are very expensive.

Good luck



-- 
Dag Nygren                               email: dag AT newtech DOT fi
Oy Espoon NewTech Ab                     phone: +358 9 8024910
Träsktorpet 3                              fax: +358 9 8024916
02360 ESBO                              Mobile: +358 400 426312
FINLAND

--
Note: To sign off this list, send a "signoff networker" command via email
to listserv AT listmail.temple DOT edu or visit the list's Web site at
http://listmail.temple.edu/archives/networker.html where you can
also view and post messages to the list.
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=