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From: std-unix@ut-sally.UUCP
Newsgroups: comp.std.unix
Subject: Re: tar or cpio?
Message-ID: <8189@ut-sally.UUCP>
Date: Tue, 2-Jun-87 04:04:10 EDT
Article-I.D.: ut-sally.8189
Posted: Tue Jun  2 04:04:10 1987
Date-Received: Thu, 4-Jun-87 05:10:53 EDT
References: <8001@ut-sally.UUCP> <8126@ut-sally.UUCP>
Sender: std-unix@ut-sally.UUCP
Reply-To: tony%uqcspe.OZ@seismo.css.gov (Tony O'Hagan)
Organization: Computer Science, Queensland Uni, Australia
Lines: 36
Approved: jsq@sally.utexas.edu (Moderator, John Quarterman)
Summary: off-line archives and big files

From: tony@uqcspe.oz.au (Tony O'Hagan)

Last year I wrote an off-line tape archive system for use on our UNIX
machines.  Tar and cpio were carefully compared to decide the appropiate
format for the tape archives.  Eventually we chose cpio because it permitted
retrieval of any pattern of files.  

About 120+ cpio files are stored on each archive tape and from bitter
experience I know that sometimes when appending/retrieving files to/from tape
an insufficient number of files are skipped.  (We count them using taprd now)
It would have been useful to write a "file label" included in the header
of each cpio file and be able to check this when reading.  I would have used it
to check the file number but I'm sure it would have other uses. 
( I would skip to the file before and check it's label when appending. )

I recently adapted the archive system from V7 to BSD 4.2 and added the
facility to drive remote tape drives using the blocking filters which fitted
in well with cpio.

[ These are useful points, though they are not problems with the data
interchange format, rather with the program that uses it.  -mod ]

	P.S.
There are a few other bugs in cpio which I had to fix for the local version.
	* creating new otherwise unstored directories with the current
	  mask (not mode 777).  (with -d switch)
	* not changing the ownership/group/permissions of existing
	  directories back to their values at the time of archiving.
==============================================================================
Tony O'Hagan		Australia: (07) 3774125  International: +61 7 3774125
University of Queensland	CSNET:	tony@uqcspe.oz	ACSnet:	tony@uqcspe.oz
Dept. of Computer Science	UUCP:	...!seismo!munnari!uqcspe.oz!tony
St. Lucia, Brisbane, 		ARPA:	tony%uqcspe.oz@seismo.css.gov
AUSTRALIA  4067	 		JANET:	uqcspe.oz!tony@ukc

Volume-Number: Volume 11, Number 42