Re: userspace block driver?

[Jeff Garzik]

Jens Axboe wrote:
> On Wed, Nov 09 2005, Jeff Garzik wrote:
>
> > Neil Brown wrote:
> >
> > > On Wednesday November 9, jgarzik@xxxxxxxxx wrote:
> > >
> > >
> > > > Has anybody put any thought towards how a userspace block driver
> > > > would work?
> > >
> > >
> > > Isn't this was enbd does? 
> > > http://www.it.uc3m.es/~ptb/nbd/
> >
> > Is there something there relevant for modern kernels?  I would sure hope 
> > I could come up with something more lightweight than that.
>
>
> I was going to say drbd, but then you did say more lightweight :-)
>
> Is nbd completely screwed these days?

nbd does more than I want.

_All_ that is needed is flipping requests <somehow> to/from userspace. 
nbd messes directly with sockets and such, which I don't want.  It does 
way too much, hardcodes way too much.

loop is a closer model to a generic userspace block device than nbd, I 
think.

Though, answering your question directly, I do get the impression that 
in-kernel nbd has been left behind in favor of drbd and enbd, out in the 
few places where nbd-ish solutions are used.

	Jeff



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/