System hang on shutdown when running freebsd-update

[Walter Hop]

[Apologies for not replying directly to the thread; I found it at https://lists.freebsd.org/pipermail/freebsd-stable/2014-October/080595.html ]

I noticed this same hang after upgrading from 10.0-RELEASE to 10.1-RC3 in a VM running under VMware Fusion, so the problem appears still present.

I could only make it happen in the single uptime just after the system was freebsd-updated from FreeBSD 10.0 to 10.1-RC3.

Here is a screenshot: http://lf.ms/wait-for-reboot.png

It did not make any progress after 2 hours of waiting. When restarting the VM, the disk was dirty.

Some interesting facts:
- Note "swapoff: /dev/da0p2: Cannot allocate memory" in the screenshot which might pose a clue. I haven’t seen this normally.
- FreeBSD does respond to ping while it is busy, so it is not a complete "freeze".
- The VM is at 100% CPU while this is going on.

I have created a snapshot of the VM in the failed state, so maybe some useful information could be retrieved from it, although I don’t have any experience with kernel debugging over VMware.

Cheers,
WH

-- 
Walter Hop | PGP key: https://lifeforms.nl/pgp