Environment

• Red Hat Enterprise Linux (RHEL) including:

  • Red Hat Enterprise Linux Server 5 (with the High Availability Add on)
• Red Hat High Availability Cluster with 2 or more nodes
• Clustered LVM (clvm) managing shared storage

• rgmanager managing service groups

  • Service contains an LVM resource (HA-LVM - CLVM variant), and that service has a failover domain specified (domain="rd1" for example):

    <resources>
      <fs device="/dev/mapper/vg_data-rd1_vol" force_fsck="1" force_unmount="1" fstype="ext3" mountpoint="/app/rd1" name="rd1fs" self_fence="0"/>
  <lvm lv_name="rd2_vol" name="rd2lvm" vg_name="vg_data"/>
    </resources>
    <service autostart="0" domain="rd1" exclusive="0" name="rd1svc" recovery="disable">
  <lvm ref="rd1lvm"/>
  <fs ref="rd1fs"/>
    </service>
  

  • Service is not allowed to start on all cluster nodes. For example, the service above is part of this failover domain, and is only allowed to start on 2 of the 3 nodes (not allowed to start on node5). The failover domain is also restricted="1":

      <failoverdomain name="rd1" nofailback="1" ordered="1" restricted="1">
        <failoverdomainnode name="node4" priority="1"/>
        <failoverdomainnode name="node5" priority="1"/>
      </failoverdomain>
  

  • The LVM logical volume is (a)ctive on the 1 cluster node that the service is not allowed to run on:

  # hostname
  node5
  # lvs
    LV               VG      Attr   LSize   Origin Snap%  Move Log Copy%  Convert
    rd1_vol         vg_data -wi-a-   6.00G