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	Mon, 24 Nov 1997 19:52:16 +1030 (CST)
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Date: Mon, 24 Nov 1997 19:52:16 +1030
From: Greg Lehey <grog@lemis.com>
To: Jacques Hugo <jacques@wired.ctech.ac.za>
Cc: questions@FreeBSD.ORG
Subject: Re: some backup questions
References: <347936EA.167EB0E7@wired.ctech.ac.za>
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In-Reply-To: <347936EA.167EB0E7@wired.ctech.ac.za>; from Jacques Hugo on Mon, Nov 24, 1997 at 10:12:26AM +0200
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On Mon, Nov 24, 1997 at 10:12:26AM +0200, Jacques Hugo wrote:
> Hi there...
>
> I'm running some backups here to a DAT drive, but I'd like
> to know if I'm doing this right or where I can improve.
>
> This is what I usually do:
>
>> mt -f /dev/nrst0 erase
>> mt -f /dev/nrst0 retension
>
> Is this ok? 

Well, it doesn't do any harm.

> Do I have to erase ("format ??") the new tape everytime?

No, you never need to do it.  You don't need to retension, either.

> Then:
>
>> tar -czvf /dev/nrst0 /usr/home/user
>
> After this, do I have to write some 'eof' stuff to the
> volume I backed up, or can I just continue with another
> file system?

Just continue.  The driver writes the EOF automatically when the tar
exits.

> I keep log of everything I back up.  And if I want to restore
> some data, I;
>
>> mt -f /dev/nrst0 rewind
>> mt -f /dev/nrst0 fsf 3 (for eg.)
>> tar -xzvf /dev/nrst0
>
> I'd like to here how you guys do it.

That's pretty much correct.  If you export an environment variable
TAPE, you can simplify things.  For example (Bourne shell and friends)

# TAPE=/dev/nrst0; export TAPE
# mt rewind
# mt fsf 3
# tar xzv

Greg