Easiest way to update jails from 9.0 to 9.1

[other at ahhyes.net]

I thought I'd post an update on this, I found the following article on 
the web which is exactly the sort of info I was after (well, it pointed 
me in the right direction anyway since I don't use ezjail and each jail 
was created manually using the process documented in the FreeBSD 
handbook + Jail manpage):

http://www.cyberciti.biz/faq/how-to-upgrade-freebsd-jail-vps/

Obviously I took care to backup all of my /etc directories from each 
jail first. So far so good though :) All my jails appear to be working 
fine.

It was pretty much a rinse and repeat of:

# make installworld DESTDIR=$JAILDIR
# mergemaster -i -C -D $JAILDIR

It was a bit laborious and time consuming, however a new "RELEASE" 
doesn't come up that often so it wasn't a big deal, unlike linux where 
there is a new distro version every couple of months.

Cheers,
Alex.