The following are suggested sub-tree sizes for a full system install.  The
numbers include enough extra space to permit you to run a typical home
system that is connected to the internet:

SYSTEM		/	/usr	/var	/usr/X11R6
alpha		50M	433M	20M	120MB (no Xserver)
amiga		27M	173M	20M	 64M
arc		47M	268M	20M	 60M
hp300		26M	120M	20M	 50M
i386		30M	172M	20M	 85M
mac68k		26M	172M	20M	(no X11)
mvme68k		26M	173M	20M	(no X11)
pmax		44M	267M	20M	 60M
sparc		35M	194M	20M	 50M

When you are in the disklabel editor, you may choose to make your entire
system have just an 'a' and 'b' partition.  The 'a' partition you set up
in disklabel will become your root partition, which should be the sum of
all the 3 main values above (/, /usr, and /var) plus some space for /tmp.
The 'b' partition you set up automatically becomes your system swap
partition -- we recommend a minimum of 32MB but if you have disk to spare
make it at least 64MB.

However, we recommend you use many seperate partitions so that users cannot
fill up your important partitions as easily, thus causing nasty denial of
service problems.  If you are extra cautious, you will make at least the
following seperate partitions: / swap /usr /var /tmp /var/tmp /home.

You can place /usr/local and /usr/X11R6 inside /usr or you can simply
create their spaces as symbolic links or as seperate partitions.