Re: [fuse-devel] FUSE and NFS

[Sven U. <sve...@gm...>]

Hello Jonathan,

> Sorry. What I want is a filesystem that keeps track of which files
> have been written to disk and keeps an extended attribute that is
> the hash of the file. It may also trigger something else to happen
> when the file is changed.

Ok.

> But the current filesystem I would have to do this on would need to
> be available on multiple machines. Hence, NFS is currently being
> used.

So, in order for this to work, you would export the FUSE filesystem,
right?  This mostly works, but depending on what your filesystem does,
can be quite slow.  In fact, if you really do want a hash for each
_file_, it will be slow, as writing a file over NFS will open and
close the file quite often (even though the application only opened
and closed the file once), so unless you are using a hash which can be
updated quite cheaply, this will take long... (this assumes NFS3, no
idea about NFS4).

You might want to rethink just why you the need arose, and whether
there's a better way to handle it (mounting via a FUSE FS local to
each computer, rather than NFS?).

> I'm fairly new to NFS as I've never set one up myself. I'm not sure
> how well FUSE and NFS work with each other. 

Well, above from the above, there's the issue of inodes (essentially,
you either manage those yourself, or you'll run into trouble sooner or
later, with either inodes running out, or files changing inodes in
midstep...) 

> Right now, my biggest concern is that I start FUSE on computer A,
> but updates to the file on computer B don't update the extended
> attribute on A.
> 
> Is there a way to set this up that would work? I hope that clarified
> things a bit.

As I said above, it will _work_ --- but will most likely be too slow
to be of much use

Sven
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