clvmd service failed with 'WARNING: Locking disabled. Be careful! This could corrupt your metadata' after OS upgrade.

Issue

• After OS upgrade from Red Hat Enterprise Linux 5u3 to Red Hat Enterprise Linux 5u5 , clvmd service failed with the following message.

$ service clvmd start
  WARNING: Locking disabled. Be careful! This could corrupt your metadata.
  1 logical volume(s) in volume group "vg1" now active
Starting clvmd:                                            [  OK  ]
Activating VGs:   connect() failed on local socket: No such file or directory
  WARNING: Falling back to local file-based locking.
  Volume Groups with the clustered attribute will be inaccessible.
  Skipping clustered volume group vg1
  3 logical volume(s) in volume group "rootvg" now active
                                                           [FAILED]

• Verified that locking_type = 3 is set correctly in /etc/lvm/lvm.conf as VolumeGroup vg1 is formatted as GFS2 fs.