Choose XML, or a GUI, or CIBS?
Life in the heartbeat2 world seems to focus on either XML or a GUI. If you are a unix scripter and would like to operate easily on hertbeat2 resources I have developed an alternative: CIBS. CIBS stands for CIB Scripts, scripts that help you easily manipulate the content of the CIB. While these CIBS are by no means a replacement for all XML in heartbeat land or an understanding of how to use the heartbeat command line tools, they may make your life easier and allow you to easily edit resources without having to constantly edit XML.
I use Vservers profusely and I run them on top of DRBD so that I can fail them over from one node to another independently using heartbeat 2. I described how to do this on the Vserver Wiki.
I have also hacked together a few special purpose OCF resource agents that meet my needs. They might be useful to you:
I hacked an OCF script together so that you can use drbd as a normal resource. If you are going to have more than two nodes in your cluster, you'd better create a location constraint that restricts the drbd device to the two specific machines where the drbd device is.
The only reason I created this is because I use DRBD 7.x and the main drbd OCF agent provided with heartbeat seems aimed at DRBD 8.x (it did not work for me). DRBD 7.x is only supported with heartbeat 1 (I am pretty sure I read that on the mailing list). Good luck getting more than one independent drbd device working with heartbeat 1.
I also wrote a VServer OCF script. This will allow you to run a vserver on any machine in a cluster where its filesystems are available.
I hacked this script from the original using the code posted on the mailing list so that it unmounts safely even when an NFS share somewhere on the system is not responding.