Re: [fuse-devel] RepFS anyone?

[Martin C. A. <ma...@pa...>]

Hi all,

On Fri, 28 Jan 2005 07:34:09 -0800 "Joshua J. Berry" <con...@co...> wrote:
> On Friday 28 January 2005 01:41, Martin C.Atkins wrote:
>...
> > When the secondary directory becomes available, replay the logfile
> > to bring it up-to-date with the primary.
> 
> What happens if changes have occurred on the server in the meantime?  (think 
> of a CVS conflict when trying to commit)

I totally agree that a "solution" to this would be nice, but I was
following the "one thing at a time" principle, and assuming (for the
moment) that the server was used primarily as a backup, and would
never change behind the client's back.

>...
> You also have to worry about this synchronization issue.  How do you handle 
> the scenario when the same files have changed on the client and server, but 
> in different ways?  You need to merge them somehow ... or throw it back to 
> the user and say "here, fix this". :)

The first step would be to assume they can't change. I believe even
this would be useful (if used with care).

The second step would be to detect when files have changed, and warn
the user (rather than just messing up) - this would be 'better'.

The third step would be to try to do something about the conflicts.

The fourth step would be ...

>..
> I agree, I would love to see an alternative to Coda (and InterMezzo).  But I 
> think such a thing will necessarily be pretty involved, because of this 
> conflict/merging issue...

Well, this is exactly the problem that Coda/Intermezzo try to solve,
so we already know how complicated the full solution is!

[As I've already pointed out, Coda was also a "user-mode filesystem"
- it just used its own kernel driver, instead of Fuse. So we're even
going about the solution in the same way!]

Martin
-- 
Martin C. Atkins				ma...@pa...
Parvat Infotech (Private) Limited		http://www.parvat.com