Repositioning /var | /tmp to avoid disk full condition

[Joseph Maxwell]

Hello,
The 3rd edition of "The Complete FreeBSD" suggest repositioning the /var
directory ( and even /tmp) to prevent filling up that partition. I
ignored it and did just that today, filled it up. So I attempted the
repositioning with the following recommended command steps and results:

     cd /var
     tar cf - . | (cd /usr/var; tar xf - )
     cd /
     rm -rf /var
     ln -s /usr/var /var

However the  'rm -rf /var' returned

     rm: /var: Device busy

After trying all known tricks to me to remove /var, I concluded that
since it was mounted from the /etc/fstab I should dismount it and remove
the directory (link point ?) and create a soft link there as
recommended. However, on rebooting boot was aborted, was thrown into
single users mode. After some findangling eventually got the system back
up as before with the /var directory, except that now it contains only
the /var/cron and /var/run directories.

The original /var contained

     /var/account:
     /var/at:
     /var/backups:
     /var/crash:
     /var/cron:
     /var/db:
     /var/games:
     /var/log:
     /var/lost+found:
     /var/mail:
     /var/msgs:
     /var/preserve:
     /var/qmail:
     /var/run:
     /var/rwho:
     /var/smtpd:
     /var/spool:
     /var/tmp:
     /var/webmin:
     /var/yp:

How can I restore the full functioning structural integrity as before,
of course the contents of the /usr/var directory was wiped out somwhere
along the way, sans log, sans mail, sans everything. Just want to
continue as before.

Thanks.

--  Joe  --