I read about this today. I plan to implement it and I will write a howto on the subject. I'm not sure of the timeline but perhaps fairly soon - let me finish the Unison project first.

You must enable “CONNECTOR - unified userspace ↔ kernelspace linker” in your kernel configuration, because drbd needs it.

Kernel Configuration| Device Drivers ---> Connector - unified userspace <-> kernelspace linker ---> [*] Connector - unified userspace <-> kernelspace linker [*] Report process events to userspace (NEW)

Partition table for DRBD|<pre> TEST </pre>

* http://gentoo-wiki.com/HOWTO_Heartbeat_and_DRBD