A.P. Lawrence

This article is from a FAQ concerning SCO operating systems. While some of the information may be applicable to any OS, or any Unix or Linux OS, it may be specific to SCO Xenix, Open Desktop or Openserver.

There is lots of Linux, Mac OS X and general Unix info elsewhere on this site: Search this site is the best way to find anything.

Unix, Xenix and ODT General FAQ

Is tar/cpio a good backup program?

tar is not; cpio is, to some degree. tar will not back up things like device nodes (and, prior to OpenServer Release 5, it will also not back up empty directories), so a tar backup will not catch anything in /dev, for example, and you will find your device nodes missing when you do your restore. cpio will catch these things.

Neither one is very good at verification. You can dd the tape to make sure you can read the whole thing, and run it through tar or cpio ... but they'll just check the file headers to make sure they make some sense. If you need better verification, try one of the products listed below. Most third-party backup programs do many things better than the standard utilities included with the OS, including things like making much better emergency recovery diskettes, byte-for-byte verification (if you want), compression, more options for things like nondestructive restore, etc. Many of us swear by them.

gnu tar is a significantly better backup utility, and is available on many archive sites listed in the Administrative FAQ. There is also a shareware tar/cpio archive checker called tapechk, written by Nigel Horne <njh@smsltd.demon.co.uk>. A demonstration version is available at ftp://garbo.uwasa.fi/unix/util/tapechk.sco.tar.Z

Commercial programs provide better solutions. The following vendors offer backup programs for SCO, Linux and many other platforms:

• CTAR
• Lone Tar
• Microlite Edge

Also see /Reviews/supertars.html