Hardware Management Console (HMC) Case Configuration Study for LPAR Management 35
hmc2 cec-green green2 max_mem: prof= 32768
hmc2 cec-green green2 max_procs: prof= 4
hmc2 cec-green green2 min_procs: prof= 1
hmc2 cec-green green2 des_procs: prof= 2
hmc2 cec-green green3 min_mem: prof= 2048
hmc2 cec-green green3 des_mem: prof= 12288 curr= 4608
hmc2 cec-green green3 max_mem: prof= 32768
hmc2 cec-green green3 max_procs: prof= 4
hmc2 cec-green green3 min_procs: prof= 1
hmc2 cec-green green3 des_procs: prof= 2 curr= 1
In Example 16 on page 34, you can see that the LPAR blue6 has 2 GB memory
configured instead of the desired 4 GB or that LPAR blue4 works currently with
one processor instead of the desired 2 processors. LPAR vio2 is down, therefore
the current values are all set to 0.
High availability considerations for HMCsThe following sections describe high availability consideration for HMCs.
Working with redundant HMCs
The HMC is mandatory for all POWER5 systems working in a partitioned
environment, and therefore the HMC is a very important hardware component.
For some environments, it might be useful to work with redundant HMCs.
There is no special installation procedure or configuration needed to work with
two HMCs. They are installed in the usual manner. Both are active and ready to
take management tasks at any time.
The HMCs are automatically notified of any changes that occur in the managed
system. If there is a change on one HMC, a couple of seconds later, it is visible
on the second one automatically. Or if the managed system sends a state or an
operator panel value, for example, when a LPAR is starting, the different states
and LED codes will be visible on both HMCs at the same time.
There is a locking mechanism to prevent basic conflicts. For the amount of time it
takes to handle an operation, the HMC gets exclusive control over the interface
of the managed system. After this operation is completed, the lock will be
released and the interface is released for further commands.
Important: When using a service agent, enable it on one HMC only to prevent
duplicated service calls.