Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building a Metropolitan Cluster Using MetroCluster/CA
Preparing an MC/ServiceGuard Cluster for MetroCluster /CA
Chapter 3 93
• If you change the LDEV number associated with a given target/LUN,
you must restart all the Raid Manager instances even though the
Raid Manager configuration file is not modified.
• Any firmware update, cache expansion, or board change, requires a
restart of all Raid Manager instances.
• pairsplit for asynchronous mode may take a long time depending
on how long the synchronization takes. there is a potential for the CA
link to fail while pairsplit is in progress. If this happens, pairsplit
will fail with a return code of EX_EWSUSE.
• In most cases, MetroCluster/CA in asynchronous mode will behave
the same as when the fence level is set to NEVER in synchronous
mode.
Installing the Necessary Software
Before any configuration can begin, you need to perform the following
installation tasks on all nodes:
• Install Raid Manager XP, which allows you to manage the XP series
disk arrays from the node. Refer to the installation instructions in
the Raid Manager XP User’s Guide.
• Edit the /etc/services file, adding an entry for the Raid Manager XP
instance to be used with MetroCluster/CA in the format
horcm<instance-number> <port-number>/udp. For example:
horcm0 11000/udp #Raid Manager instance 0
See the file /opt/cmcluster/toolkit/SGCA/Samples/services.example.
• Install MetroCluster with Continuous Access XP on all nodes
according to the instructions in the MetroCluster with Continuous
Access XP Release Notes.
• Install MC/ServiceGuard if it is not already present, and configure
the MC/ServiceGuard cluster according to the procedures outlined in
Managing MC/ServiceGuard. The MAX_CONFIGURED_PACKAGES
parameter in the cluster configuration file should be set to 1 or more,
depending on the number of packages that will run on the cluster.