Doing multiple backups on the 6000 8mm tape

[Patrick Torre]

jd9014 at cca.ucsf.edu (Joe DeBattista) writes:

>Greetings,
>   I'm in the process of setting up my backups on my RS/6000 model
>320, version 3002.  I'd like to be able to dump all my filesystems
>on the same tape, but the backup command is refusing to cooperate.
>I'm trying to use the command 
>   backup -0 -f /dev/rmt0.1 file_system_name

>What I thought this would do would be to use the non-rewind feature
>and then let me run the next backup comand for the next filesystem.
>What happens, however, is that the backup command still rewinds to
>the beginning before starting the next backup.  I'd be grateful for
>any insights.
>-- 
>                            Joe DeBattista

This got me at first too.
actually the backup is retarded and just assumes 
that the tape is being rewound by the device.   
Ever notice how little time it takes for backup to rewind
/dev/rmt0.1 ? (tape drives are not THAT fast).

Just ignore the message.   

By the way, you wont fit much on a 2.3 gig 8mm tape if you 
dont up the blocks per output operation ( -b 100 or something), 
this should get the tape drive to stream. (or whatever) 
you'll get little more than 1/2 a gig at the default.


Check out "tcopy /dev/rmt0" as a way to veriry that more than 
one backup has been written to the tape.

Question ??

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

help me.

-- 
Patrick Torre @ Dun and Bradstreet Software, Inc (404) 239-2061
{emory,gatech}!nanovx!msa3b!torre