Re: VFS mediator?

Pavel Machek (pavel@suse.cz)
Mon, 18 Mar 2002 20:25:02 +0100


Hi!

> > > I have experimented with using NFS for that -- start a local daemon that
> > > exports a virtual filesystem and mount that. The great bonus is that it's
> > > platform independent -- it works on Solaris, HP-UX and even Ultrix just as
> > > well. Other projects have become more important, however, and I haven't
> > > finished it. If you're interested, drop me a line.
> >
> > There are several of these and also some folks using the coda interface
> > to do the same work, as the coda interface is sometimes better suited.
>
> ... for some kinds of work.
>
> First of all, "VFS mediator" is simply a userland filesystem. That's
> precisely what it is - filesystem that talks to a process. We've got
> quite a few of them and which one fits the task depends on the task.
>
> * NFS (v2,v3): Portable. And that's the only good thing to say
> about it - it's stateless, it has messy semantics all over the place and
> implementing userland server requires a lot of glue.

Does not work... If you mount nfs server on localhost, you can deadlock.

> * CODA: nice if you want commit-on-close semantics and basically
> want a lot of regular files. More or less portable, userland side doesn't
> require much glue. Has a nice local caching and as the result bad for any
> RPC-style uses.

And the only one that works when r/w mounted on localhost.
Pavel

-- 
(about SSSCA) "I don't say this lightly.  However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/