Bug 208736

Summary:	freebsd-update does not work when /var/empty is a RO filesystem
Product:	Base System	Reporter:	Alan <alan>
Component:	bin	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	New ---
Severity:	Affects Many People	CC:	amd64, emaste, lukasz, peter
Priority:	---
Version:	10.3-BETA2
Hardware:	Any
OS:	Any

Description Alan 2016-04-12 05:29:55 UTC

Making /var/empty its own read-only filesystem is common on systems with root on ZFS, and is the suggested configuration in the FreeBSD wiki (https://wiki.freebsd.org/RootOnZFS).  freebsd-update should probably detect such configurations when running with the "upgrade" option, and either abort gracefully with a warning or ignore the steps it would normally take on /var/empty.  Currently it stops with very little diagnostic output.

I've confirmed this on several amd64 systems configured with root on ZFS while attempting to upgrade via 'freebsd-update upgrade -r 10.3-RELEASE".