Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!rutgers!uwvax!oddjob!mimsy!cvl!umd5!brl-adm!adm!mike@BRL.ARPA
From: mike@BRL.ARPA
Newsgroups: comp.unix.wizards
Subject: Re:  On backups
Message-ID: <7295@brl-adm.ARPA>
Date: Thu, 7-May-87 21:59:48 EDT
Article-I.D.: brl-adm.7295
Posted: Thu May  7 21:59:48 1987
Date-Received: Sat, 9-May-87 06:50:49 EDT
Sender: news@brl-adm.ARPA
Lines: 16

It seems to me that the basic assumption that you make is that
your users are not working with large files, so that a significant
number of days worth of incremental dumps can fit onto a single
Eagle disk.

For facilities like BRL with heavy scientific and engineering applications,
it is not uncommon for a single scientist to produce 300+ Mbytes of
"new" (different) data.  Each machine (even the aging VAXen) tends to
have >2 Gbytes each, and we have serveral dozen machines.
Your strategy, while nice, does not address this type of environment.

When I was visiting Martin Marietta in ~1980, they described their
backup system (for their PDP-11/70 IS/1 UNIX systems) that is virtually
the same as your system.  (sorry).
	Best,
	 -Mike