freebsd stable - Dec 2014 - System hang on shutdown when running freebsd-update

> >/  Another update. I narrowed down the issue due to /sbin/init being
replaced. This might be the magic that freebsd-update does to make the crash
happen. (Although there might be more situations that cause a hang.)
> />/
> />/  I can completely reliably trigger the hang on a default
10.1-RELEASE install on UFS2 in VMware Fusion with the following procedure:
> />/
> />/  # chflags noschg /sbin/init
> />/  # cp -Rp /sbin/init /sbin/init2
> />/  # rm -f /sbin/init
> />/  # mv /sbin/init2 /sbin/init
> />/  # chflags schg /sbin/init
> />/  # reboot
> />/  => Hang after "All buffers synced."
> /These commands do not trigger the issue here on a 10.1-RELEASE on VMware
> Player, but do it in a real system with the same release, both i386.
> When I last freebsd-updated this latter machine from 10.0 to
> 10.1-RELEASE, I also remember seeing the hang on shutdown.
>
> Hope it helps,
> Juan
The hang occurs again when running freebsd-update to install the 
security advisories of today on a 10.1-RELEASE i386. No problem under 
VMWare, same version.

Best regards,
Juan

On Wed 2014-12-10 14:13:28 UTC+0100, Juan Ram?n Molina Menor (listjm at
club-internet.fr) wrote:
> > >/ Another update. I narrowed down the issue due to /sbin/init
being
> > >replaced. This might be the magic that freebsd-update does to make
the
> > >crash happen. (Although there might be more situations that cause
a
> > >hang.)
> >
> > />/ I can completely reliably trigger the hang on a default
> > />/ 10.1-RELEASE install on UFS2 in VMware Fusion with the
following
> > >>/ procedure:
> > />/
> > />/  # chflags noschg /sbin/init
> > />/  # cp -Rp /sbin/init /sbin/init2
> > />/  # rm -f /sbin/init
> > />/  # mv /sbin/init2 /sbin/init
> > />/  # chflags schg /sbin/init
> > />/  # reboot
> > />/  => Hang after "All buffers synced."
> > /These commands do not trigger the issue here on a 10.1-RELEASE on
VMware
> > Player, but do it in a real system with the same release, both i386.
> > When I last freebsd-updated this latter machine from 10.0 to
> > 10.1-RELEASE, I also remember seeing the hang on shutdown.
> >
> > Hope it helps,
> > Juan
> 
> The hang occurs again when running freebsd-update to install the 
> security advisories of today on a 10.1-RELEASE i386. No problem under 
> VMWare, same version.
> 
> Best regards,
> Juan
A FreeBSD 10.1-REL amd64 VM here also hangs after /sbin/reboot is run,
after installing updates with freebsd-update. The VM runs under
VirtualBox on an Ubuntu 14.04 host.

On hard-resetting the VM, it appears the filesystem (UFS) wasn't flushed:

Dec 11 00:29:52 vbox-freebsd kernel: WARNING: / was not properly dismounted

Regards
Andrew