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From: architec@cutmcvax.cs.curtin.edu.au (Phil Dench )
Newsgroups: comp.sys.sgi
Subject: Re: Multiple archives on one tape
Message-ID: <architec.658764950@cutmcvax>
Date: 16 Nov 90 14:15:50 GMT
References: <90319.090207W0L@psuvm.psu.edu>
Sender: usenet@uniwa.uwa.oz (USENET News System)
Organization: Curtin University of Technology, Computing Science
Lines: 44

W0L@psuvm.psu.edu (Bill Lasher) writes:

>We have an environment with a large number of users (~400) on a group of
>machines.  I am looking for a simple way for these people to archive files.
>We have 1/4" cartridge tapes, and tar (or bru) won't allow you to append
>archives.  The result is the users have lots of tapes with small files on them.
>Any suggestions that won't require the users (they are students) to buy *REAL*
>expensive tapes?

>Bill


I asked the same question myself several months ago. This is the
most helpfull reply I received from Dave Olson.


> If you can accept multiple archives on the tape, then this sequence will
> work.  If you keep track of the archive number, you can use mt fsf # to
> space to the one you want to list or extract from.
> Unfortunately, there is a bug in the 3.2 tape driver that causes this
> sequence to not work reliably for all drives; when it doesn't work, the
> first archive can be overwritten.  So if the 'mt status' doesn't show
> EOD, then don't do the tar cv!

> first archive: tar cv ....
> 2nd thru N: mt feom; mt status; tar cv ...

> listing, you can do:
> tar vtf /dev/nrtape; tar vtf /dev/nrtape; tar vtf /dev/nrtape; ...
> or
> mt fsf N; tar vt

> If you don't specify the nrtape device, it will rewind at the end, but it
> will NOT rewind or reposition before writing if you are at BOT, FM, or EOD.

> Hope this helps.

>    Dave Olson


... and make sure you do the 'mt status'.


Phil