CB1, INC.

Further to what I just said...

drbd 8.2.5 will build and install without having to compile the kernel:

download drbd-8.2.5.tar.gz into /tmp then:

apt-get install build-essential linux-kernel-devel \
    linux-headers-2.6.24-16 linux-headers-2.6.24-16-server
cd /usr/src
ln -s linux-headers-2.6.24-16-server linux
tar xzvf /tmp/drbd-8.2.5.tar.gz
cd /usr/src/linux
make mrporper
cd /usr/src/drbd-8.2.5
make clean all
make install

Then, as kbe mentioned:

copy  /lib/modules/2.6.24-16-server/kernel/drivers/block/drbd.ko \
     to /lib/modules/2.6.24-16-server/ubuntu/block/drbd/drbd.ko