From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: Versioning Plugin Date: Fri, 11 Nov 2005 18:24:42 -0800 Message-ID: <4375526A.6080404@namesys.com> References: <200511111359.39715.jgilmore@glycou.com> <200511111656.04891.pvh@uvic.ca> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <200511111656.04891.pvh@uvic.ca> List-Id: Content-Type: text/plain; charset="us-ascii" To: Peter van Hardenberg Cc: reiserfs-list@namesys.com Peter van Hardenberg wrote: >On November 11, 2005 05:59 am, John Gilmore wrote: > > >>Does anybody remember GoBack? It was a versioning >>system for windows 95/98 that was incredibly flexible and useful. Tracked >>all changes to the whole disk. Old versions of a file? no problem. grab an >>old version of a directory for referance temporarily? easy. Got a virus? >>revert the whole HD, and then grab the newer copies of your documents and >>saved games as needed. >> >> > >My thoughts on this: > >The versioning would be an audit plugin. When the file is modified, tag the >current version, copy it into a sub-directory (oh, I don't know, say >file/.revisions/), and disable write access to it. You might not >even need extended filesystem attributes for this, but they would be handy >for tagging particular versions. > >Copy-on-write would make this action extremely cheap, only adding a couple of >extra writes to make it work. > >Given working resource directories, COW, and the ability to set plugins, this >might be a relatively easy hack to implement. Given an efficient xpath shell, >you could even create a view of your drive on a particular day. > >If you had a file that was changing often, perhaps you could set an attribute >on that file which told it only to clone the file every once in a while. > >Come to think of it, a userspace daemon could run in the background and >replace the need for a plugin, which is probably the better solution. Then >you just need COW and files which can contain resources. > >-pvh > > > Yup, sounds good to me, it just needs someone to write it. A later version could implement a special compression plugin that spanned the multiple file versions..... Hans