Ming Zhang wrote: > On Fri, 2005-11-11 at 16:56 -0800, 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/<number/date>), 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. > > > if a file is opened, modified 2 times, then closed. u will only generate > 1 version right? so "When the file is modified" is inaccurate.
How about "When the transaction was completed?" Why does it matter? >>Copy-on-write would make this action extremely cheap, only adding a couple of >>extra writes to make it work. > > > add 1 line at the beginning of a 100MB text file will make this uncheap. Who has to work with 100 meg text files? And why has this person not broken them down into 100 kilobyte text files? Storage efficiency isn't really an issue there... Anyway, I think the main win is from copy-on-write for the whole file.
