VFS journaling... similar technology

[David Leimbach]

I was reading the following thread.
http://leaf.dragonflybsd.org/mailarchive/kernel/2005-07/msg00024.html

I think it makes sense to point out that there are other systems that
are linux/BSD like that have VFS messaging.  Andrew Morton has adopted
v9fs which is an implementation of the 9P filesystem protocol, done
through messages, and hooks into the linux VFS.

In fact, it should be possible to now use the Plan9Ports "venti"
system which does something similar to the idea of a realtime-backup
system. Venti is traditionally used as the block storage backend for a
"Fossil" filesystem on Plan 9 systems.  It effectively implements
something like a "write once" repository [yes, you can dump old
blocks] and for some people this eliminates the need to for CVS as
people can pull old files from the log per-se from previous snapshots
that are taken.

It's pretty fascinating stuff.  Even if DragonFly never does 9P all of
these things could be done through this messaging interface that you
now have.  It'd be really cool for us Inferno/Plan9 geeks to have a
translation layer to 9P and back on DragonFly.  We could instantly tie
DragonFly into our grids.  And 9P is pretty danged reliable... I can
mount my files on a japanese server from Seattle and the connection
never seems to break [of course they have stability algorithms for
that].

Lookin good guys!  It might be helpful for ideas to poke around in
these more esoteric OSes... some of this kind of work has, in fact,
been done before [just not exactly the same way].

Dave