> Anyways, I need a rough idea of how much space it takes to build and
> install /usr/src in it's entirety for one arch (i386).  Also, if /usr/src
> is seperate from /usr, how much "breathing room" does /usr need during 
> the install.

I have /usr/src on a roughly 220Mb partition (I think); this contains the
i386 sources plus the Mac and Amiga sources (I build only the i386, though),
the XFree86 sources, and the objects (/usr/obj is a symbolic link to
/usr/src/obj).  I can build all of NetBSD, with some room to spare, if I've
remembered to do a "make clean" under XFree86.

> Also any hints on how to install after rebuild on a running system
> would help.  With the binary snapshots, I've just been moving dirs out
> of the way and untarring from scratch to avoid any problems with
> zorching current processes and done okay (I am backing up, it's just I
> only have one system right now).  This has worked okay for me for now...
> but working from the src tree will be a bit different, no?

Yes and no; if you install a recent source over ancient sources, you wind
up with lots of confusion due to files that have moved.  However, you don't
wind up killing running processes by overwriting their source :-).  I
generally preserve things I've changed (especially my kernel config file!),
then "rm -rf" the installed sources and re-install the new sources from tape.
Unless you make massive changes, you don't need to preserve the old sources
en masse.

One wrinkle:  once you start using shared libraries, you must be extremely
careful about new builds (unless you wait long enough that the major number
increments :-); if you install a miscompiled shared libc.so that your
existing binaries attempt to use, you cease to have any fun at all in a
hurry.  Make a tar of /usr/lib/lib* on floppy just in case (and compile a
copy of tar statically linked!).  (If you have waited long enough between
libc changes, your existing programs searching for libc.so.3.x will ignore
libc.so.4.0, so you're safe until you overwrite your installed binaries.
Test a few things before typing "make install"!).


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