The following commands move files from the OS partition to the home partition no data is loss during this proccess, it is very important that you dont make any stupid typos or you can say hello to your restore cd :)
cd /usr
find src | cpio -pdmuv /home/users
find local | cpio -pdmuv /home/users
find X11R6 | cpio -pdmuv /home/users
find man | cpio -pdmuv /home/users
find doc | cpio -pdmuv /home/users
rm -rf /usr/src /usr/local /usr/X11R6 /usr/man /usr/doc
ln -s /home/users/src /usr
ln -s /home/users/local /usr
ln -s /home/users/X11R6 /usr
ln -s /home/users/man /usr
ln -s /home/users/doc /usr
df
Once you have done this you are very unlikly to see the yellow or red warning lights ever agian, unless you do some serious installing or sun release a mega security patch.