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From: gmoff@ccu1.aukuni.ac.nz (Moffat)
Newsgroups: comp.unix.aix
Subject: Re: Doing multiple backups on the 6000 8mm tape
Message-ID: <1991Feb20.105914.17233@ccu1.aukuni.ac.nz>
Date: 20 Feb 91 10:59:14 GMT
References: <3366@ucsfcca.ucsf.edu> <1532@msa3b.UUCP>
Organization: University of Auckland, New Zealand.
Lines: 27

torre@msa3b.UUCP (Patrick Torre) writes:

>I leave the tape in the machine all week and add 3 backup files 
>to the tape each night ( /u / and /usr ).
>what is a good way to backspace to the beginning of this group
>of files, verify that the backups are good, and leave the tape
>positioned for the next nights backups??
>tctl bsf 3 , seems to leave the tape in a bad spot (right before
>the eof mark "before" the first or second backup.

I don't know about this infernal 8mm drive (I might post my problems after
I've calmed down and stopped cursing *B^) but with traditional tape drives,
where you write the tape marks (eof) yourself, to back up n tape files you
do a 'bsf n+1; fsf'. (assuming there is a tape mark after the last file)
This is because fsf/bsf effectively count the marks they 'pass' and stop
immediately beyond them (is that clear? it is to *me*)

>                                                  and if this is the 
>first 3 files on the tape it I cant use tctl 4.

Write a small 'identification' file on the tape first

-- 
    Graeme Moffat,                        Phone : +64 9 737 999  x8384 
    Computer Aided Design Centre,         Fax   : +64 9 366 0702
    School of Engineering,		  Mail  : Private Bag, Auckland, NZ
    University of Auckland		  Email : g.moffat@aukuni.ac.nz