HP TMS zl Module Security Administrator's Guide

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Managing TMS zl Modules
Configuring High Availability Clusters
PCM navigation tree. An HA cluster created using the NIM Create
Cluster function automatically removes the Participant device. You
must select the “TMS zl” group in the PCM Navigation Tree and then
select the cluster’s Master module to view the Participant device
status.
■ When an existing HA cluster (configured via CLI / WebUI) is imported
into NIM, it is important to delete the Participant device from the PCM
navigation tree, as instructed in the documentation. If the Participant
is not deleted, it could result in duplicate rows been displayed in the
High-Availability tab. If duplicate rows are displayed, they can be
removed by rediscovering both the devices. You can also click the
“View” button on the High-Availability window.
■ The Modify Cluster function will create downtime because both
modules must be rebooted at the same time for these changes to be
applied.
■ The Modify Cluster function can create a role reversal of Master and
Participant since both modules must be rebooted at the same time to
apply the modified configuration on both modules. It is not guaran-
teed which module will reboot first and become the Master module.
In practice, the Master is booted first, causing a failover to the
Participant, which can then be booted. The original Master is likely
to finish booting first since it started rebooting first, and will remain
the Master.
■ The Remove Cluster function always leaves the Participant as the
active device with the VLAN configuration since the Participant
cannot be removed from the cluster directly by the Master. The Master
module must be removed from the cluster first and rebooted, which
causes the Master module's configuration to be copied to the Partic-
ipant module and the Participant to temporarily take over as the new
Master. In the second phase of the cluster removal, the former Partic-
ipant module, which is now the Master, is removed, but it retains the
module configuration. If you wish the current Master to remain as the
active device with the current configuration, you must first cause a
failover (by booting the Master module) to the Participant so it
becomes the new Master and can be removed.
■ When the Remove Device from Cluster function (only enabled for a
Master device) is executed on a TMS zl module, the original Master
device in the cluster is removed from the cluster. Removing the Master
causes the Participant, if any, to take on the role of Master. This
creates a single device cluster with a Master that acted as Participant,
and the original Master will lose its IP configuration.