Unable to mount Logical Volume when cluster is disabled in HA-LVM Cluster

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux 5.5
  • HA-LVM cluster
  • Ext3 filesystem
  • Postgresql

Issue

  • While disabling postgresql service in an HA-LVM 3 node cluster, it is not possible to mount the Logical Volume on local disks. The purpose of mounting is to test TSM restore of postgresql data.

Resolution

These steps should never be performed on a production HA-LVM cluster as it would corrupt the LVM meta data. Also this requirement would never occur in production systems. This was for a test set up and mainly done for maintenance.

  • Stop cluster services on all the three nodes. Use the command:

        #clusvcadm -d <service name>

  • On one of the nodes edit  /etc/lvm/lvm.conf and comment out the line:

        #volume_list = [ "rootvg", "@test.test.in" ]

  • Now run the command :

         #lvchange -ay <Logical Volume Name>

  • Then mount the Logical Volume that needs to be mounted on to the local disk.

To re-enable cluster:

  • Unmount the Logical Volume

  • Edit the /etc/lvm/lvm.conf and uncomment the line:

    #volume_list = [ "rootvg", "@test.test.in" ]

  • Start cluster service using:

     #clusvcadm -e <service name>

Root Cause

  • The required Logical Volume was not specified in volume_list.

This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.

Comments