[comp.sys.hp] Backup in diff. filesets on a DAT/tape under HP-UX

dsn@elctr.UUCP (Dan Soeren Nielsen) (05/31/91)

Hey Again


As I am looking for a DAT-tape drive with high capacity in ran into another
problem, how do I store/backup the different files for individual retrival ?.

What I want to do is to store each disk as a saveset/archive on the tape, and
all disks in my installation shall be backed up on the same tape !?. How to
do that !, I have been looking at the tar the cpio etc. but none of these
supports the creation of diff. files on the same tape.

Some body outthere must have the same problem and perhaps solved it ?

Thanks in Advance

Dan Soren Nielsen

ElektronikCentralen e-mail dsn@elctr.dk 

jco@donner.cis.ufl.edu (John C. Orthoefer) (05/31/91)

To back up many filesystems to one tape.  You should have the non-rewinding
device built for the DAT.  Then you dump (we use dump, tar works the same
way) to that device.  It then puts a eot at the end of the file and two
eot's at the end of the tape.  You can't write over early backups with out
losing the later ones.  However, you can add to the tape.

Then you use the mt command to play with the tape. 

	mt -t /dev/mt/0n1 [rew|fsf|eom|off]
	      ^^^^^^^^^^^
		What ever the non rewinding device is for your machine.

There are other commands but those are the most useful one.  

	rew:  rewinds a tape
	fsf:  forward step file, this moves past the next eot mark.  You can
	      also put a number after this one as in mt -f /dev... fsf 2
	      which moves you to the begining of the 3rd file on the tape
	      (past the first two eot marks.)
	eom:  end of media, this moves to the end of tape (not the physical
	      end) and positions the head between the two eot marks.
	off:  rewinds the tapes and ejects it.

Quick note to any HP people out there:
	1. Why did you change the -f to -t?
	2. Why don't you implement status and absolute step file asf?
	status tells you what file your on with the tape and asf does a
	rewind and fsf.

later
jco

ps. If I impress you how about a job, I'm looking  1/2 * :-)

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jtb@cs.ed.ac.uk (Jo Blishen) (06/03/91)

In article <JCO.91May31085030@donner.cis.ufl.edu>, jco@donner.cis.ufl.edu (John C. Orthoefer) writes:
> 
> To back up many filesystems to one tape.  You should have the non-rewinding
> device built for the DAT.  Then you dump (we use dump, tar works the same

Does this mean dump works OK on a DAT drive?  Which version of HP-UX?
We are running 7.05 and we were told that dump isn't supported on our
1300S SCSI DAT drive.

Jo

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