Searches are very useful, but sometimes there's no getting around
doing some actual reading.
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#NEW-H...
includes some relevant material.
As I said previously, you can't do that easily. The easiest way to do
that is to back up both partitions, delete them, re-create them with
new sizes, and restore them from the backups. Moving /var/mail to
/usr/mail (and putting a symlink to it back on /var) is probably a lot
easier, and will probably solve your problem, but it isn't technically
what you asked for.
Yep. I recommend redirecting the mail somewhere else, so it doesn't
pile up.
I already gave the standard pointers to the FreeBSD web site's list of
support sources, but if you want a newsgroup, there's only one:
comp.unix.bsd.freebsd.misc. Most of the others are gateways of the
official mailing lists, and in general posting to them will not work
effectively.