[9fans] Fossil Venti question...

[9fans] Fossil Venti question...

[David Leimbach]

Perhaps I'm just having difficulty absorbing the relationship.  Fossil
is the filesystem server that [optionally?] uses Venti for block
storage?  I don't believe my Plan 9 system [currently down due to
hardware failure :(] had Venti but did have fossil.

Do I really want to use Venti with Fossil?  Why?  I've read some about
how it works but I guess I've missed out on the "use cases" of it.

Fossil seems to have the capability of being the write once system,
making a great archival system, but I don't quite understand the
"why?" for Venti just yet.

Any clarification or pointer to documentation would be greatly
appreciated.  I guess I'm not as interested in what it is as why it
is.

Dave

Re: [9fans] Fossil Venti question...

[Tiit Lankots]

> Perhaps I'm just having difficulty absorbing the relationship.  Fossil
> is the filesystem server that [optionally?] uses Venti for block
> storage?  I don't believe my Plan 9 system [currently down due to
> hardware failure :(] had Venti but did have fossil.

Yes. Fossil and venti are (almost) completely unrelated. With the exception
of course that fossil knows about venti and can make a use of it
if you want it to.

> Fossil seems to have the capability of being the write once system,
> making a great archival system, but I don't quite understand the
> "why?" for Venti just yet.

Venti is WORM. Fossil is just a natty filesystem that can take a snapshot
of your entire system - say - after each 15 minutes and a complete
read only snapshot to a venti - say - once a day. It's kinda handy
once you get used to it.

OK, executive style:
Venti is an archival file system that has WORM semantics (+ several other
advantages, read the relevant paper in plan9.bell-labs.com/plan9 [I can't
give you the correct URL because it seems to be down at the time I'm
writing this]).
Fossil is an (the?) file system for Plan 9 that knows how to take  
snapshots,
optionally to venti for eternal storage.