topic Re: Tar command in Operating System - HP-UX

Tar command

kenlo — Thu, 05 Dec 2002 11:45:47 GMT

Anybady know the tar option to ignore the file origin directory in tape, use "tar option" to restore the any current directory.
For example, tar cvf /dev/rmt/0m /etc/hosts. Want use "tar 'option' /dev/rmt/0m 'current directory'"

Ken

Re: Tar command

Steve Steel — Thu, 05 Dec 2002 11:53:58 GMT

Hi

see 2.3 if your restore whole archive

2.0 tar

2.1 Save a Directory Path With `tar'

If the f option with `tar' is omitted it will take /dev/rmt/0m as the
default tape device file. If your tape drive device file differs, add the
`f' option.

tar cv /directory (absolute path not recommended)

cd /directory; tar cv . (relative path recommended)
or
tar cv ./dir1 ./dir2 ./dir3 ..... (for multiple directories)

2.2 What is written on the `tar' tape?

tar tv
tar tv >/tmp/index

2.3 Restore with `tar'.

cd /directory ; tar xv (relative tar restore)

2.4 `tar' via network.

Write a `tar' tape on a remote computer that owns a DAT/DDS drive.

cd /relative_path
tar cvf - . | remsh name -l user "cat - | dd of=/dev/rmt/0m bs=10k"

Restore a `tar' tape from a remote computer that owns a DAT/DDS drive.
cd /relative_path
remsh name -l user dd if=/dev/rmt/0m bs=10k | tar xvf -

2.5 Good to know about tar!

`tar' is an easy command and can be used as interchange format. These are
the only advantages.

I would like to advise you not to use `tar' to back-up a couple of gigabytes,
because `tar' does not support `regular expressions'. Selected file
retrieval is only possible by this command:

tar xv `tar t | grep "^user/drawings*"

To backup and recover to another directory with great options you need fbackup/frecover.

Regards

Steve Steel

Quote of the moment
-------------------
"We are drowning in information but starved for knowledge."
-- John Naisbitt

Re: Tar command

Chris Wilshaw — Thu, 05 Dec 2002 11:54:24 GMT

Tar isn't very sophisticated in this respect

The best you can hope for is to create the archive using

cd /etc
tar cvf /dev/rmt/0m hosts

This will then create the archive with no leading directories, so that you can then use

cd /your_new_dir
tar xvf /dev/rmt/0m hosts

Re: Tar command

Stefan Farrelly — Thu, 05 Dec 2002 12:06:13 GMT

HP's tar cant do it, but the gun version can. You can download the gnu version of tar from;

http://hpux.cs.utah.edu/

Re: Tar command

RAC_1 — Thu, 05 Dec 2002 12:09:47 GMT

In order to avoid tar backups with absolute path names I always use
tar -cvf /dev/rmt/rmt/0m ./etc/*

But in case you do take it absolute path names you can restore wiht pax.

cd /your_dir
pax -rv -s '/^\///' < /dev/rmt/0m

Re: Tar command

Steve Steel — Thu, 05 Dec 2002 12:44:43 GMT

Hi

Worst case scenario is a chroot

In the future use fbackup since tar is a simple soul.

Restore a complete directory

/etc/frecover -xi/directory
/etc/frecover -x -i/directory1 -i/directory2

When restoring a directory, `frecover' will not overwrite an existing
file, except if the -o option is used.

It may be nice to recover relative somewhere in a directory like /tmp/local.
To restore relative, you must go first to the directory with cd, and then
use the X or F option.

cd /tmp/local; /etc/frecover -xvXi /directory
(with directory tree path )
cd /tmp/local; /etc/frecover -xvFi /directory
(without path, only files names)

Regards

Steve Steel

Quote of the moment
-------------------
"We are drowning in information but starved for knowledge."
-- John Naisbitt

Re: Tar command

harry d brown jr — Thu, 05 Dec 2002 12:56:58 GMT

As of this moment, Anil is the only one that has it right. You MUST use pax to restore a ABSOLUTE PATH backup to a ALTERNATE (RELATIVE) directory, though I find this syntax a little easier:

cd to desired directory
pax -r -s ',^/,,' -f file.tar

(no need for back slashes)

live free or die
harry

Re: Tar command

RAC_1 — Thu, 05 Dec 2002 13:17:09 GMT

Harry I was going to put that syntax. I read man page for pax many times but did not understand anything, particularly -s options syntax

It is easy to remember
/^\///

four forward slashes and one backward slash

Re: Tar command

James R. Ferguson — Thu, 05 Dec 2002 13:25:00 GMT

Hi:

Harry's use of the comma (",") as a delimiter makes the *substitution* ('-s') 'pax' syntax easier to read than using a "/" delimiter and having to escape its dual meaning as part of a filename or directory and as a delimiter. *Any* character can be used as a delimiter. Note that the syntax mirrors that of 'sed'.

Regards!

...JRF...