From: utzoo!decvax!ittvax!shp
Newsgroups: net.unix-wizards
Title: Thoughts on system backups
Article-I.D.: ittvax.670
Posted: Wed Apr  6 15:02:42 1983
Received: Thu Apr  7 03:50:28 1983

An article appeared recently about doing system backups under UNIX using
dump and/or tar.  I shall assume the author was speaking of a 4.xbsd system
since he mentioned an 11/750.  He talked about several problems, which 
included:

- end of tape recognition
	There have been published fixes to the mag tape device driver to
	solve the end of tape problem.  Make sure your tape drive is up to
	the proper ECO rev level, particularly TU77's.  There are several
	hardware revs to TU77's that are somewhat related to the end of
	tape problem.  I've never experienced multiple volume tape problems
	using dump.  On our TU77 we had to use 5 2400' tapes per file
	system.  The TU78 requires 2 2400' tapes.  Not once has dump messed
	up and gone off the end of tape.

- restoration of entire directories
	It's true you cannot use /etc/restor to restore an entire directory
	like you can with tar, however, it's trivial to get /etc/restor to
	restore directories.  First you use dumpdir to get a list of all
	the files in the directory to be restored; make a second copy of
	this list.  Edit the first copy so that it contains only file
	names (dumpdir also lists inodes).  Edit the second copy so that
	it is a shell script containing mv(1) instructions to rename the
	inodes to their proper file names.

	/etc/restor x `cat first_copy`     .... does the actual restore ....

	second_copy			   .... renames the files ....



	- sam praul
	  ...decvax!ittvax!shp