Forget the Brain... DLM in Ubuntu 12.04

This is a stream-of-research post - don't look for answers here, though I do link some interesting articles.

I'm in the process of preparing my cluster for expansion, and in the midst of installing a new server I inadvertently installed 12.04.1 instead of 11.10.  The rest of the cluster uses 11.10.

Some important distinctions:

• 12.04 seems to support CMAN+Corosync+Pacemaker+OCFS2 quite well.
• The same is not for certain on 11.10.
• 12.04 NO LONGER has dlm_controld.pcmk.
• Trying to symlink or fake the dlm binary on 12.04 does not appear to work, from what my memory tells me.

You CAN connect 12.04's and 11.10's Corosyncs and Pacemakers, but from as far as I can tell, only if you Don't Need DLM.

I Need DLM.

So, I am trying understand CMAN a bit better.  Here's some interesting articles:

Configuring CMAN and Corosync - this explains why some of my configurations failed brutally - http://people.redhat.com/ccaulfie/docs/CmanYinYang.pdf

Understanding CMAN and Corosync - written earlier than the above document - http://people.redhat.com/ccaulfie/docs/Whither%20cman.pdf

In summary - the CMAN-related binaries load Corosync, but CMAN itself is a plugin for Corosync, providing quorum support. 

Uuuhhhgggg...

CMAN generates the necessary Corosync configuration parameters from cluster.conf and defaults. 

Corosync appears to be the phoenix that rose from the, well, ashes of the OpenAIS project, since that project's page announces cessation of OpenAIS development.  Corosync deals with all messaging and whatnot, and it appears thus that CMAN is providing definitive quorum information to Corosync even though Corosync has its own quorum mechanisms (which, if I read it right, are distilled versions from earlier CMAN incarnations).