dump/restore, how to reduce slice size

[John Levine]

>>> # df -h
>>> Filesystem     Size    Used   Avail Capacity  Mounted on
>>> /dev/ad4s1a      2G    206M    1.6G    11%    /
>>> devfs          1.0k    1.0k      0B   100%    /dev
>>> /dev/ad4s1e    3.9G     13M    3.6G     0%    /tmp
>>> /dev/ad4s1f     40G     25G     12G    67%    /usr
>>> /dev/ad4s1d     31G    3.6G     24G    13%    /var
>>> procfs         4.0k    4.0k      0B   100%    /proc
>>> /dev/ad2s1f     39G     25G     10G    71%    /mnt
>>> devfs          1.0k    1.0k      0B   100%    /var/named/dev
>>>
>>>
>>> as you can see /dev/ad4s1f is 40G and /dev/ad2s1f is 39G
>>> but on ad4s1f only 25G used.
>>>
>>> How can I dump /dev/ad4s1f and restore it on /dev/ad2s1f?

You can't.  ad4s1f has 25G of files, but ad2s1f only has 10G of
free space.  You need a bigger disk.

If you're just moving things around, I agree that a $100 USB
disk is the best way to store backups temporarily.

R's,
John