topic Re: tape backup using tar in Operating System - HP-UX

tape backup using tar

Steve_3 — Tue, 01 Aug 2000 20:21:32 GMT

Need help with tape backup using tar. How do I do a stack? When I do "tar cvf /dev/rmt/0m /tmp" it backup the /tmp and rewind. How do I get it not to rewind, b/c I want to contiue backups on the tape.
HP-UX 11.0

Thanks,
Steve

Re: tape backup using tar

Rick Garland — Tue, 01 Aug 2000 20:24:51 GMT

Use the no-rewind device. Example, do the ioscan -fnCtape and this will show the devices. There are other device names associated with the same physical device. One example would be /dev/rmt/0mn. The 'n' is specifing no-rewind.

Re: tape backup using tar

Rick Garland — Tue, 01 Aug 2000 20:33:46 GMT

As a note, tar may not be the best choice for doing backups. If using the UNIX utilities, check out cpio or dump. tar is OK but the other utilities are better. Depends on what you are doing...

Re: tape backup using tar

Tom Danzig — Tue, 01 Aug 2000 20:36:10 GMT

If you want to add another file or directory to an existing tar tape backup, use the r option for tar. For example:

tar cvf /dev/rmt/0mn /tmp
(note use of no rewind device file)

To add /usr to your /tmp tar backup,

tar rvf /dev/rmt/0mn /usr

Re: tape backup using tar

Philip Chan_1 — Wed, 02 Aug 2000 01:07:46 GMT

Hi Tom,

Correct me if I'm not, I thought the "r" flag is no good for tape archives (saw this from man page).

Steve, if I'm correct then you should use the "u" flag instead,

eg. tar uvf /dev/rmt/0m

and I don't suggest you relying on non-reminding device while appending files.

Rgds,
Philip

Re: tape backup using tar

Andreas Voss — Wed, 02 Aug 2000 05:24:33 GMT

Hi,

another method is to use the mt command:
mt eod will wind the tape to the last end of data. Then you can append with a new tar command.

Greetings

Andrew

Re: tape backup using tar

Tom Danzig — Wed, 02 Aug 2000 16:00:58 GMT

Philip,

Your correct. It should be u, not r.

Tom