Re: [fuse-devel] [PATCHSET] CUSE: implement CUSE

[Mike Hommey <mh@glandium.org>]

On Sat, Aug 30, 2008 at 02:30:32PM +0200, Tejun Heo wrote:
> Hello,
> 
> Archie Cobbs wrote:
> >> Thought about that but it's really no different from nbd or loop
> >> depending on your application and block devices don't really implement
> >> the file operations so it won't have too much in common with FUSE.
> > 
> > I think BUSE would be useful. For one, it allows you to avoid problems with
> > the extra caching you get with a loopback device. And NBD is too limiting
> > for some applications.
> > 
> > For my half-ignorant analysis of the caching issues, see:
> >   http://code.google.com/p/s3backer/wiki/PerformanceConsiderations#Caching
> > 
> > This is also an example of an application where NBD doesn't suffice.
> > 
> >> Also, there's the complication of going out to disk for more memory cases.
> > 
> > Not sure what you mean exactly (my fault), but it seems BUSE would have fewer
> > places for memory problems (including deadlocks) than loopback over FUSE,
> > which is the only way to do this kind of stuff now.
> 
> Yeah, compared to loopback over FUSE, anything would have less
> problem. :-) I don't know much about nbd but it's pretty much solving
> the same problem so I think it's logical to extend nbd including
> giving it a new transport if necessary?  Or is there something
> fundamentally better when it's done via FUSE?

My gutt feeling is that it would have less overhead when done via FUSE
than through nbd, but that could be wrong.

Mike