topic Re: tar file to tape in Operating System - Linux

tar file to tape

heaman1 — Thu, 25 Jun 2009 05:15:36 GMT

I have a tape which have data in it ( make by other backup tool ) , I want to use tar to append data to it , I tried "tar -cvf dev file" , it will overwrite the data in the tape , can advise how to preserve the existing data ? thx

Re: tar file to tape

Michal Kapalka (mikap) — Thu, 25 Jun 2009 05:53:57 GMT

hi,

this is a example for solaris but its the same for all Unix / Linux .

http://www.cyberciti.biz/faq/linux-tape-backup-with-mt-and-tar-command-howto/

http://www.cyberciti.biz/tips/solaris-tar-command-to-backup-data-on-tape-device.html

- if there is a other backup, you should use another tape.

mikap

Re: tar file to tape

heaman1 — Thu, 25 Jun 2009 06:10:46 GMT

thx reply

when I use tar -rvf dev file , it pop the below error in my RH server , can advise what is wrong ? thx

tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now

Re: tar file to tape

Michal Kapalka (mikap) — Thu, 25 Jun 2009 06:14:35 GMT

hi,

if you wona use tape for archiving you need to handle the tapes with mt, this small tool handle the operation with the Magnetic Tape.

http://www.cs.inf.ethz.ch/stricker/lab/linux_tape.html

mikap

Re: tar file to tape

Steven Schweda — Thu, 25 Jun 2009 06:41:26 GMT

> I have a tape which have data in it ( make
> by other backup tool ) [...]

What, exactly, is "other backup tool", and
does it write "tar" archives?

> when I use tar -rvf dev file , [...]

If the thing on the tape is not a "tar"
archive, then what do you expect from "tar
-r"?

http://www.gnu.org/software/tar/manual/html_node/Operation-Summary.html#SEC41

[...]
'--append'
'-r'

Appends files to the end of the archive. See section How to Add Files to Existing Archives:
'--append'
[...]

See the part where it says "Appends files to
the end of the archive"? It's talking about
a "tar" archive, not any old pile of bits on
a tape.

If you can get "mt" to forward-space to the
end of the data on the tape, and if you use
a non-rewinding tape device, then "tar -c"
might work.

> [...] I tried "tar -cvf dev file" [...]

As usual, showing the actual commands you
used might be more helpful than vague
descriptions and interpretations. In this
case, "dev" is particularly uninformative.

Re: tar file to tape

Dennis Handly — Sat, 27 Jun 2009 21:27:10 GMT

You also asked this in the HP-UX forum:
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1348023

Re: tar file to tape

Steven Schweda — Sat, 27 Jun 2009 23:27:52 GMT

> You also asked this in the HP-UX forum:

In some cases it helps to ask the same
question repeatedly until you get an answer
you like. In other cases, you just waste
everyone's time.

Hmmm. Which case is this?