Bug 995193

***Update to case description***

Going back through the case, I opened this with the wrong problem description.  It was *NOT* using software RAID (mdadm) devices.  The command is failing when using a mirrored LV device.

Description should be:

"Steps to Reproduce:
1. create mirrored LV device, e.g.:
   # lvcreate -L 200m -m1 -n mirrorlv testvg /dev/vdb1 /dev/vdc1
2. # vgchange -an testvg
3. set clustered attribute on VG,
  # vgchange -cy testvg
4. try to remove clustered attribute on VG by using 
   # vgchange -cn testvg --config 'global {locking_type = 0}'

Actual Results:
WARNING: Locking disabled. Be careful! This could corrupt your metadata.
  Unable to determine exclusivity of mirrorlv
  Mirror logical volumes must be inactive when changing the cluster attribute.

The mirrored LV is inactive and this should be successful.

Expected Results:
Successfully remove the clustered attribute flag"

Created attachment 784936 [details]
output from vgchange -cn testvg --config '{global locking_type = 0}' fail using mirrored LV

Output requested on vgchange -vvvv command.

Fix committed upstream:

commit abc89422af75fa9e20d24285d1366e4631cb8748
Author: Jonathan Brassow <jbrassow>
Date:   Mon Aug 12 13:56:47 2013 -0500

    Mirror: Fix inability to remove VG's cluster flag if it contains a mirror
    
    According to bug 995193, if a volume group
        1) contains a mirror
        2) is clustered
        3) 'locking_type' = 0 is used
    then it is not possible to remove the 'c'luster flag from the VG.  This
    is due to the way _lv_is_active behaves.
    
    We shouldn't allow the cluster flag to be flipped unless the mirrors in
    the cluster are not active.  This is because different kernel modules
    are used depending on whether a mirror is cluster or not.  When we
    attempt to see if the mirror is active, we first check locally.  If it
    is not, then we attempt to check for remotely active instances if the VG
    is clustered.  Since the no_lock locking type is LCK_CLUSTERED, but does
    not implement 'query_resource', remote_lock_held will always return an
    error in this case.  An error from remove_lock_held is treated as though
    the lock _is_ held (i.e. the LV is active remotely).  This blocks the
    cluster flag from changing.
    
    The solution is to implement 'query_resource' for the no_lock type.  It
    will report a message and return 1.  This will allow _lv_is_active to
    function properly.  The LV would be considered not active remotely and
    the VG can change its flag.

[root@virt-012 ~]# lvcreate -m 1 -n mirror -L1G clustered
  Logical volume "mirror" created

waited for sync

[root@virt-012 ~]# vgchange -an clustered
  0 logical volume(s) in volume group "clustered" now active
[root@virt-012 ~]# vgchange -cn clustered --config 'global {locking_type = 0}'
  WARNING: Locking disabled. Be careful! This could corrupt your metadata.
  Volume group "clustered" successfully changed


Marking verified with 

lvm2-2.02.100-4.el6.x86_64
lvm2-cluster-2.02.100-4.el6.x86_64
kernel-2.6.32-420.el6.x86_64

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-1704.html