1) If you are running a 64 bit version of OpenVZ on the Hardware Node, don't expect your 64 bit guests to work on a 32 bit host.

2) If you get an error saying asm/bitsperlong.h missing, then run make sure /usr/src/linux/include/asm/bitsperlong.h -> /lib/modules/2.6.31-gentoo-r10/build/include/asm-generic/bitsperlong.h is linked.

3) Do not be afraid.