[Pacemaker] Raid RA Changes to Enable ms configuration -- need some assistance plz.

[Errol Neal]

Hi all. I was hoping to get some help with my configuration. I'm kinda 
stuck at the moment. 

I've made some changes to the Raid1 RA to implement a ms style 
configuration (you can see a diff here http://pastebin.com/Q2nbF6Rg 
against the RA in the github repo)

I've modeled my ms implementation heavily on the SCST RA from the ESOS 
project (thanks Marc!). 

Here is my full pacemaker config:

http://pastebin.com/jw6WTpZz

I'm running on CentOS 6.5 using Pacemaker, and CMAN available from the 
distro.  

I'll explain a little bit about what I'm doing then tell you folks where 
I think I need a bit of assistance or a push in the right direction

The Raid1 RA changes I made are because I want to assemble the same 
RAID1 members on two different hosts. The slave should assemble it in 
readonly mode. Using the SCST RA, I can offer two paths to the same LUN 
from two distinct systems, one standby, one active. In order to keep 
things good and consistent, the master of the MD resource also needs to 
be master of the SCST resource (i'm using the example here 
http://clusterlabs.org/doc/en-
US/Pacemaker/1.1/html/Pacemaker_Explained/s-resource-sets-
colocation.html).
So if you can't already tell, this is YAA to create a highly available 
open storage system :)

My understanding is that in order for N to start, N+1 must already be 
running. So my configuration (to me) reads that the ms_md0 master 
resource must be started and running before the ms_scst1 resource will 
be started (as master) and these services will be force on the same 
node. Please correct me if my understanding is incorrect. When both 
nodes are up and running, the master roles are not split so I *think* my 
configuration is being honored, which leads me to my next issue. 

In my modified RA, I'm not sure I understand how to promote/demote 
properly. For example, when I put a node on standby, the remaining node 
doesn't get promoted. I'm not sure why, so I'm asking the experts. 

I'd really appreciate any feedback, advice, etc you folks can give. 

Thanks, 

Errol Neal