ZFS corruption using zvols as backingstore for hvm VM's

[Roger Pau Monné]

On Wed, Nov 18, 2020 at 11:58:27AM -0800, Brian Buhrow wrote:
> 	hello Roger.  Sorry for the confusion.  I've been running NetBSD, or
> trying to, in both PV and HVM modes.  Here is a mesage I sent to the
> port-xen at netbsd.org mailing list a few days ago, detailing what I found
> with running NetBSD in any mode under Xen as a domu.  Unfortunately, I
> don't think I can provide a trace  of a crash to the xen server when the

OK, I'm not really able to reproduce this myself, so if you get those
crashes again can you please make sure you have a serial attached to
the box so that you can provide some trace?

> HVM host misbehaves because I've had to move on in my work to get things
> working and I found a working combination of  NetBSD and ZFS that let's me
> proceed.  I've seen some discussion in the Xen documentation that suggests
> one can run a Xen dom0 in a domu guest, allowing for sand box testing of
> what you're describing without having to devote hardware to the issue.  Am
> I correct in this and where might I find instructions on how to do it?

You can test a nested PV dom0, but not a nested PVH dom0, which is
what FreeBSD uses to run as dom0.

> 
> In any case, here's what I found.

Thanks, I'm sure this will e helpful to others.

Roger.