Description of problem:

This problem exists when accessing/setting the quorum disk by label or by device.

The quorum disk as specified in cluster.conf is unable to work on /dev/mapper
devices.   Customers would like the quorum to be on a robust device.  Although
the quorum can be configured to run on /dev/dm-N, these can change depending on
various san related factors.


Scenario 1:

        <quorumd label="test_qdisk" status_file="/tmp/foo" interval="1"
min_score="1" tko="10" votes="2">
                <heuristic interval="3" program="ping reliable.host.com -c1 -t1"
score="1"/>
        </quorumd>

This is problematic, as the qdisk daemon scans through /proc/filesystems and
grabs the first match (usually the /dev/sde, not /dev/dm-N) which voids the use
case for multipath.

A possible (and tested) is to return the last match in the partition list 
(cman/qdisk/proc.c), not the first, if people have quorum on multipath, the
multipath device is probablyl what they want.


Scenario 2:

     <quorumd device="/dev/mapper/whatever" status_file="/tmp/foo" interval="1"
min_score="1" tko="10" votes="2">
                <heuristic interval="3" program="ping reliable.host.com -c1 -t1"
score="1"/>
        </quorumd>


While this device is found, it is not counted towards the votes in cman_tool status.

Scenario 3:


     <quorumd device="/dev/qvg/qlv" status_file="/tmp/foo" interval="1"
min_score="1" tko="10" votes="2">
                <heuristic interval="3" program="ping reliable.host.com -c1 -t1"
score="1"/>
        </quorumd>


Customers may wish to put the quorum on an lvm device (in case they have a
failing disk on the cluster node).  This works, but using the
/dev/mapper/qvg-qlv does not work.

Version-Release number of selected component (if applicable):
 
device-mapper-multipath-0.4.7-8.el5
cman-2.0.60-1.el5

How reproducible:

Every time
Steps to Reproduce:
1. Configure cluster
2. Add qdisk to point to /dev/mapper/Name
3. start cman , start qdisk, note qdisk votes dont count or show in cman_tool nodes.
  
Actual results:

Spend some time finding out the various options that work, and wont work.

Expected results:

devices created by device-mapper to work.

Additional information:

Tested on 5.1 beta, same results.