1.3. Clustering

Support for redundant ring for standalone Corosync, BZ#722469
Red Hat Enterprise Linux 6.2 introduces support for redundant ring with autorecovery feature as a Technology Preview. Refer to Section 2.7, “Clustering” for a list of known issues associated with this Technology Preview.
corosync-cpgtool, BZ#688260
The corosync-cpgtool now specifies both interfaces in a dual ring configuration. This feature is a Technology Preview.
Disabling rgmanager in /etc/cluster.conf, BZ#723925
As a consequence of converting the /etc/cluster.conf configuration file to be used by pacemaker, rgmanager must be disabled. The risk of not doing this is high; after a successful conversion, it would be possible to start rgmanager and pacemaker on the same host, managing the same resources.
Consequently, Red Hat Enterprise Linux 6.2 includes a feature (as a Technology Preview) that forces the following requirements:
  • rgmanager must refuse to start if it sees the <rm disabled="1"> flag in /etc/cluster.conf.
  • rgmanager must stop any resources and exit if the <rm disabled="1"> flag appears in /etc/cluster.conf during a reconfiguration.
pacemaker, BZ#456895
Pacemaker, a scalable high-availability cluster resource manager, is included in Red Hat Enterprise Linux 6 as a Technology Preview. Pacemaker is not fully integrated with the Red Hat cluster stack.