freebsd stable - May 2019 - trying to expand a zvol-backed bhyve guest which is UFS

On May 19, 2019, at 9:46 PM, tech-lists <tech-lists at zyxst.net> wrote:
> Hi,
>
> context is 12-stable, zfs, bhyve
>
> I have a zvol-backed bhyve guest. Its zvol size was initially 512GB
> It needed to be expanded to 4TB. That worked fine.
>
> The problem is the freebsd guest is UFS and I can't seem to make it see
> the new size. But zfs list -o size on the host shows that as far as zfs is
> concerned, it's 4TB
>
> On the guest, I've tried running growfs / but it says requested size is
> the same as the size it already is (508GB)
>
> gpart show on the guest has the following
>
> # gpart show
> =>        63  4294967232  vtbd0  MBR  (4.0T)
>          63           1         - free -  (512B)
>          64  4294967216      1  freebsd  [active]  (2.0T)
>         4294967280          15         - free -  (7.5K)
>
> =>         0  4294967216  vtbd0s1  BSD  (2.0T)
>           0  1065353216        1  freebsd-ufs (508G)
>  1065353216     8388544        2  freebsd-swap  (4.0G)
>  1073741760  3221225456               - free -  (1.5T)
>
> I'm not understanding the double output, or why growfs hasn't
worked on
> the guest ufs. Can anyone help please?

Given the above, the freebsd-ufs partition can't grow because there is a  
freebsd-swap partition between it and the free space you've added at the  
end of the volume.

You'd need to delete the swap partition (or otherwise move it to the end of
the partition on the volume) before you could successfully growfs the  
freebsd-ufs partition.

Cheers,

Paul.

On Sun, May 19, 2019, 6:59 PM Paul Mather, <paul at gromit.dlib.vt.edu>
wrote:
> On May 19, 2019, at 9:46 PM, tech-lists <tech-lists at zyxst.net>
wrote:
>
> > Hi,
> >
> > context is 12-stable, zfs, bhyve
> >
> > I have a zvol-backed bhyve guest. Its zvol size was initially 512GB
> > It needed to be expanded to 4TB. That worked fine.
> >
> > The problem is the freebsd guest is UFS and I can't seem to make
it see
> > the new size. But zfs list -o size on the host shows that as far as
zfs
> is
> > concerned, it's 4TB
> >
> > On the guest, I've tried running growfs / but it says requested
size is
> > the same as the size it already is (508GB)
> >
> > gpart show on the guest has the following
> >
> > # gpart show
> > =>        63  4294967232  vtbd0  MBR  (4.0T)
> >          63           1         - free -  (512B)
> >          64  4294967216      1  freebsd  [active]  (2.0T)
> >         4294967280          15         - free -  (7.5K)
> >
> > =>         0  4294967216  vtbd0s1  BSD  (2.0T)
> >           0  1065353216        1  freebsd-ufs (508G)
> >  1065353216     8388544        2  freebsd-swap  (4.0G)
> >  1073741760  3221225456               - free -  (1.5T)
> >
> > I'm not understanding the double output, or why growfs hasn't
worked on
> > the guest ufs. Can anyone help please?
>
>
> Given the above, the freebsd-ufs partition can't grow because there is
a
> freebsd-swap partition between it and the free space you've added at
the
> end of the volume.
>
> You'd need to delete the swap partition (or otherwise move it to the
end
> of
> the partition on the volume) before you could successfully growfs the
> freebsd-ufs partition.
>
Even if you do all that, you won't be able to use more than 2 TB anyway, as
that's all MBR supports.

If you need more than 2 TB, you'll need to backup, repartition with GPT,
and restore from backups.


Cheers,
Freddie

Typos due to smartphone keyboard.
>