Re. http://mail-index.netbsd.org/netbsd-users/2003/07/09/0002.html

I second the recommendation to read The NetBSD Guide.

To more directly answer some of your questions, thought:

 * The default NetBSD layout has 3 real partitions (at least on port i386).
   One is the root partition (/), one is swap (for virtual memory; unusable
   for files), and one is for /usr (/usr).

   A swap partition isn't absolutely required, but unless you have more
   RAM than you can use, you probably want some swap space.  (I think that
   you can arrange to swap to files, but by reserving a *partition* for
   swap, you guarantee that there will be space for virtual memory; you
   can't make that guarantee if the space isn't reserved.)

   As for having /usr on a seperate partition...that's something of a
   debatable point.  You don't *need* to have it seperated.  Some people
   do have just one big / partition (where /usr is just a regular subdir).
   Other people put /var, /home, and perhaps others, on their own partitions.
   The value of a small root (/) partition is that if something happens to
   disasterously wreck your system, you're more likely to be able to get
   the small, core / material to work.  Also, if the system needs to repair
   the disk filesystem before use, a small / can be repaired much more
   quickly than the larger /usr.

   So the answer is that it's somewhat inertia and tradition that split off
   the small / and the large /usr, while the swap partition is probably
   one that you want to keep for now.

 * The "other two partitions" that you might have seen are probably just
   the ones traditionally (on port i386) labeled "c" and "d".  These are
   not actually slices out of your total disk.  On port i386, "d" is the
   "whole, raw disk", while "c" is "the whole disk used by NetBSD".  I'm
   a little fuzzy why the both are  needed, but the distinction is mostly
   relavent if you dual-boot your computer.  (On my systems, I just use
   NetBSD.  Even so, the "c" partition starts where the "a" partition starts,
   which is on sector 63.  "d" starts at sector 0.)

   (I tend not to think of c & d as real partitions, in part because
   they overlap with each other and with the other partitions.  But if by
   a "partition" one simply means a label for a segment of disk space, then
   c & d are partitions.  In either case, they aren't normally of concern
   to you; they don't "use up" space from the rest of your disk, since they
   are just handles for "whole disk" regions.)

   I.e., don't worry about these two partitions.  They are essentially
   free, using up only 2 slots in NetBSD's "disklabel" (NOT the same as
   the BIOS disk partition table).  NetBSD allows up to 16 partitions,
   now (it used to only allow 8, but that started to be restrictive for
   some users who wanted to slice their disks up more finely).

 * If you copied files to /usr, or any subdirectory of /usr, you should
   probably have had plenty of space.  If you copied to / (or any sub-dir
   NOT in /usr), you probably ran out of space very quickly.

   / is traditionally small on NetBSD.  /usr is where most of the free space
   goes.

   Because /var (including /var/mail) and /home reside on / by default,
   / *should* have some slack space.  But if you're copying something like
   a full X distribution to /, I'm not surprised that you ran out of
   space.  (^&

 * Again, echoing something someone already said: NetBSD comes with X.  You
   don't need to download X from an external source.  (You can install NetBSD
   without X, but it's part of the basic distribution sets and unless there's
   a particular reason you want to do otherwise, you're probably best served
   by using the version of X that ships with NetBSD.)

-- 
  "I probably don't know what I'm talking about."  http://www.olib.org/~rkr/