Making installworld got stuck on SunFire v20z (Freebsd 8.0)

[Lucas Wang]

I tried to install Freebsd 8.0 on one of our lab machines, which is
SunFire v20z. After successfully installing it from CD, I followed the
following steps trying to update the kernel and world:

cvsup
make buildworld
make buildkernel
make installkernel
reboot
mergemaster -p
make installworld

Everything was fine until the `make installworld` process run for a while and then got stuck, 
after that it won't respond to Ctrl-C. When I tried to login from another tty, it 
doesn't respond either. I even tried installing the machine from scratch
several times, and at different times it got stuck when installing different libraries. 

I would really appreciate any ideas about why this could happen or how
to solve it.

Lucas