snapshotting/versioning filesystems (was: subhurds etc.)

[olafBuddenhagen]

Hi,

On Wed, Nov 04, 2009 at 10:46:48AM +0100, Arne Babenhauserheide wrote:
> Am Sonntag, 1. November 2009 13:52:47 schrieb olafBuddenhagen@gmx.net:

> > The original idea for versioning filesystems was to automatically
> > keep track of individual changes, and it failed magnificently. 
> 
> As far as I know they didn't have atomic commits back then - am I
> right in that? 

Not sure what you mean here... If you are talking about atomic VCS
commits, that's irrelevant here -- there is no concurrency involved
anyways.

Also, not all approaches for versioning filesystems build on standard
VCS.

> > Well, actually the snapshotting functionality is kind a side effect
> > of atomic updates, which comes almost for free. But it's generally
> > seen as a feature for easing backups.
> 
> How exactly do they differ from a normal file system with a
> Mercurial/Git backend for revisioning with a time-based commit
> schedule? 

Well, moving stuff between the main store for the "live" files and some
VCS backend for the revisions is complex and inefficient... But aside
from such technical details, there is probably no difference. Which is
just what I said one or two mails ago :-)

-antrik-