If you have a system running FreeBSD 4 (4.9 was the most recent release at the time this document was written), it is possible to switch to DragonFly "in-place" through downloading the DragonFly source and compiling it.
uname -a
will tell you what version you are running.
Note: FreeBSD 5 versions will not work for this upgrade.
rm -rf /usr/src
rm -rf /usr/obj
mkdir /usr/obj
pkg_add ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages-4-stable/Latest/cvsup-without-gui.tgz
rehash
fetch http://www.dragonflybsd.org/community/dragonfly-cvs-supfile
Comment out the lines that say:
*default prefix=/home/dcvs
*default release=cvs
and uncomment the lines that say:
#*default prefix=/usr
#*default release=cvs tag=.
Run cvsup using that config file.
cvsup dragonfly-src-supfile
You now will have the DragonFly source files in /usr/src.
Note: the newly created file /usr/src/UPDATING
will have the
most up-to-date instructions on updating your system; double-check it
before proceeding.
cd /usr/src
make buildworld
make buildkernel
rm -rf /usr/include
mkdir /usr/include
make installworld
make installkernel
make upgrade
sync
reboot
You can repeat the cvsup/build/install steps on
this page to keep your system up to date with the changing
DragonFly codebase. (You will not have to repeat the
make upgrade_etc
step.)