upgrading 9.3 / ZFS v28

[andrew clarke]

On Mon 2014-11-17 07:33:12 UTC-0800, David Newman (dnewman at networktest.com) wrote:

> >> Greetings. For a system running 9.3-RELEASE with ZFS v28 on the root
> >> partition (I did this manually long ago), are there any gotchas for
> >> upgrading to 10.1?

> Hmmm...this could have gone better for me:
> 
> To install the downloaded upgrades, run "/usr/sbin/freebsd-update install".
> root at boonen:~ # freebsd-update install
> Installing updates...chflags: ///var/empty: Read-only file system
> 
> Normally, freebsd-update returns a reboot-and-proceed message at this
> point. Also, this system has no /var/empty partition.
> 
> How to proceed?
> 
> Thanks!

Ah yes, I encountered that error too. I think you'll find you do have
a /var/empty judging from the above error. On my system:

$ zfs list | grep empty
zroot/var/empty              14K   239G    14K  /var/empty

$ zfs get readonly zroot/var/empty
NAME             PROPERTY  VALUE   SOURCE
zroot/var/empty  readonly  on      local

So this is necessary before you run freebsd-update:

# zfs set readonly=off zroot/var/empty

Obviously, set readonly=on after freebsd-update has finished:

# zfs set readonly=on zroot/var/empty

Regards
Andrew