Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.unix Subject: Re: Multigeneration File Systems Message-ID: <4153@utzoo.UUCP> Date: Mon, 30-Jul-84 15:32:22 EDT Article-I.D.: utzoo.4153 Posted: Mon Jul 30 15:32:22 1984 Date-Received: Mon, 30-Jul-84 15:32:22 EDT References: <503@sri-arpa.UUCP> Organization: U of Toronto Zoology Lines: 14 The only version-numbering file system I've ever heard of that actually sounded good was the one CMU designed for their Spice project. (Don't know if it was/is implemented the way the tech report described it, but that's another story.) They took the view that (by default) once you created a file, it was immutable -- any attempt to change it resulted in creation of a new file, i.e. a new version number. This was automatic and inescapable, and applied to *all* attempts to change the file -- there was no way to alter an existing version at all. The idea was that old versions would be migrated, automatically and fairly quickly, out to laser disk or some similar bulk-storage medium, cheap enough and big enough that you could afford to save everything forever. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry