Playing with drbd8 on Ubuntu, loosely following these instructions, and I ran into a couple problems.
First, you need to use a kernel that has the drbd module as there is no drbd8-module-source, -server definitely has the drbd module, -virtual did not. Instructions about building the drbd module are old.
My secondary was also stuck in a connection state of “WFBitMapT”. I noticed the secondary was Ubuntu jaunty while the primary was Ubuntu intrepid. Upgrading the primary to jaunty resolved this.
I saw the error “local disk flush failed with status -95” in the logs and wasn’t entirely sure about it but eventually found an explanation that made some sense and made me not worry about it.
drbd (/etc/init.d/drbd) doesn’t start on startup on it’s own. Most of the debugging information you’re looking for is in /proc/drbd or in your syslog output in /var/log. The only trouble is deciphering what is good and what is bad.