Re: [PATCH v2 0/3] Add support for NetBSD gntdev

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Fri, Nov 30, 2012 at 10:21:02AM +0100, Roger Pau Monné wrote:
> > And I don't like the idea of software doing things in my back.
> > And, beside this, I don't think local vs remote is the right criteria.
> > There are remote filesystems which may play nice with vnd. There
> > are local filesystems that may not play nice with vnd.
> 
> I would agree with you if this was a DomU crash, but in this case the
> crash happens in the Dom0, and every DomU that the system might be
> running crashes completely. This is not acceptable in any way from my
> point of view.
> 
> I think we should not expect the user to be aware of this kind of
> problems. If we cannot guarantee that the vnd driver is functional for
> all filesystems, we should not use it. From my point of view reliability
> should always come before performance.

In my POV, the admin show know what he's doing. This includes be aware of the
limitations of the software he uses. A 50% performances loss just "in case"
is not accetpable. Or at last last there should be a way for the admin
to revert to an acceptable configuration, performance wise, without
hacking and rebuilding from sources.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--