Some notes on RootOnZFS article in wiki

[Scot Hetzel]

On 12/22/09, krad <kraduk at googlemail.com> wrote:
>
>
> 2009/12/22 Andriy Gapon <avg at icyb.net.ua>
>
> > on 22/12/2009 13:02 krad said the following:
> >
> > >
> > > Are there still issues with using zvols for swap? If not you don't need
> a
> > > slice for swap and can get rid of gmirror entirely.
> >
> > Is this supported at all _on FreeBSD_?
> > Even, if yes, one drawback is that you wouldn't be able to use zvol swap
> as a dump
> > device.
> >
> >
> > --
> > Andriy Gapon
> >
>
> Even is you use a dedicated zvol for crashdump only?
>

Opensolaris uses a seperate zvol for crash dumps, so I gave it a  try
and created a zvol.

zfs create -V 8G zroot/dump
zfs set checksum=off zroot/dump

But when dumpon executes, it tells you that dumps are not supported to
zfs zvolumes.

dv8t01# dumpon /dev/zvol/zroot/dump
dumpon: ioctl(DIOCSKERNELDUMP): Operation not supported

Scot