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There are many archival tools for Unix, with varying degrees of availability. To make matters more confusing, many of them can write each other's formats.

I am seeking more information on their relative merits, and why I would want one over another (in differing circumstances).

The landscape of archivers, as I understand it (only considering F/LOSS software):

Tar family archivers

CPIO family archivers


  • The MirBSD PAX included w/ Linux distros


  • dump included with your OS/distro

Other Archivers

  • 7zip
  • zip
  • dar

The Question

I am aware of this comparison, showing that dump beats (old) tar and cpio for dealing with various anomalies in the file system and exactly replicating its contents. However, dump is mostly oriented towards file-system-level archiving and doesn't get great support on Linux (at least Linus isn't very interested in keeping it running).

In general, why would I choose one of these archivers, particularly tar/cpio/pax, over another, and why? Which one should I generally reach for first?

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closed as not a real question by Hauke Laging, slm, Chris Down, Anthon, htor May 18 '13 at 10:18

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

This question is too broad. A short look at the article which you have linked makes clear that a "complete" answer does not fit the Q&A format of this site. – Hauke Laging May 17 '13 at 22:05
Just a quick note: star can be seen as a portable and filesystem independent replacement for the ufdump utility. Star supports incremental backups and restores and uses the same basic algorithm as ufsdump / ufsrestore. Star is even typically 30% faster than the historical dump/restore implementation. – schily Sep 10 at 14:39

1 Answer 1

cpio is a standard format, each of the others (except possibly for pax) has quirks. Second best (because it is very portable) is GNU tar.

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The cpio archive format is very limited and was abandoned by POSIX because it is not extendable. – schily Sep 10 at 14:40
@schily - cpio was not abandoned by POSIX - the pax utility is required to read/write cpio archives, though it defaults to writing USTAR type archives - the same way GNU tar does. i disagree with this answer that either cpio or GNU tar should be preferred to pax - which can (more or less) handle both formats, but can also portably extend the USTAR archive format to the pax archive format (also handled by GNU tar) and so deal with very long filenames and much else. – mikeserv Oct 24 at 11:41
@mikeserv You are confusing archive formats with archival programs in your comment. Both tar and cpio have been in the first POSIX version. The cpio progam however was added late on request by AT&T because AT&T told their customers that cpio is the upcoming new standard. This happened around 1990 and is widely known as the tarwars. Both cpio and tar at that time suffered from deficits in the command line interface. As a result of the tar wars, the program pax was defined and standardized and added to SUSv2 (1997). Cpio and tar have been removed with SUSv3 (2001). – schily Oct 26 at 11:21
Cont: Unfortunately, pax is more or less a mixture of the CLIs from cpio and tar and suffers from both CLI problems. This may be why enhanced tar implementations like star (1982) and gtar (1989) are more popular than pax. – schily Oct 26 at 11:23
Cont. What I was talking about is the cpio archive format that suffers from the problem that is rather is five incompatible formats. Every time, you like to enhance the cpio archive format, you need to create a completely new archive variant that cannot be read by previous archivers. This is why the cpio archive format was declared deprecated by POSIX after Sun (in 1997) made a proposal on how to create an enhanceable format based on the tar archive format. The new format is part of an approved POSIX version since the SUSv3 went stable in december 2001. – schily Oct 26 at 11:29

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