Replacing Failed Components; Nodes; Adapters - IBM AIX HACMP SG24-5131-00 Hardware User Manual

8.3 Replacing Failed Components

From time to time, it will be necessary to perform hardware maintenance or
upgrades on cluster components. Some replacements or upgrades can be
performed while the cluster is operative, while others require planned
downtime. Make sure you plan all the necessary actions carefully. This will
spare you a lot of trouble.

8.3.1 Nodes

When maintaining or upgrading a node, cluster services must usually be
stopped on the node. This means down time for the applications usually
running on this node, at least during the takeover to other nodes.
Consider the following points when replacing the whole or components of a
node:
• Make sure you have at least the same amount of RAM in the replacement
system.
• If your applications have been optimized for a particular processor or
architecture, ensure that the new node is the same type of system.
Uniprocessor applications may run slower on SMP systems.
• Slot capacity of the new node must be the same or better.
• Check the appropriate documentation for a proper adapter placement in
your new node.
• The license of your application may be dependent on the CPU ID. You
may need to apply for a new license before trying to bring the new node
into service.

8.3.2 Adapters

In order to replace or add an adapter, the node must be powered off. This
means down time for the applications usually running on this node, at least
during the takeover to other nodes.
Consider the following points when replacing or adding adapters in a node:
• Make sure that the adapter is your problem and not faulty cabling. Bad
cables are much more common than defective adapters. Most network
and SSA cables can be changed online. Do some testing, for example,
exchange the cables or try to connect to another port in your hub to see if
the hub is your problem.
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