High Availability Using The Hmc - IBM Power 710 Technical Overview And Introduction

For more details about HMC and the possible network connections, see Hardware
Management Console V7 Handbook, SG24-7491.
The default mechanism for allocation of the IP addresses for the service processor HMC
ports is dynamic. The HMC can be configured as a DHCP server, providing the IP address at
the time that the managed server is powered on. In this case, the FSPs are allocated an IP
address from a set of address ranges predefined in the HMC software. These predefined
ranges are identical for Version 710 of the HMC code and for previous versions.
If the service processor of the managed server does not receive a DHCP reply before time
out, predefined IP addresses will be set up on both ports. Static IP address allocation is also
an option. You can configure the IP address of the service processor ports with a static IP
address by using the Advanced System Management Interface (ASMI) menus.
Note: The service processor is used to monitor and manage the system hardware
resources and devices. The service processor offers two Ethernet 10/100 Mbps ports as
connections. Note the following information:
Both Ethernet ports are visible only to the service processor and can be used to attach
the server to an HMC or to access the ASMI options from a client web browser using
the HTTP server integrated into the service processor internal operating system.
When not configured otherwise (DHCP or from a previous ASMI setting), both Ethernet
ports of the first FSP have predefined IP addresses:
– Service processor Eth0 or HMC1 port is configured as 169.254.2.147 with netmask
– Service processor Eth1 or HMC2 port is configured as 169.254.3.147 with netmask
For the second FSP of IBM Power 770 and 780, these default addresses are:
– Service processor Eth0 or HMC1 port is configured as 169.254.2.146 with netmask
– Service processor Eth1 or HMC2 port is configured as 169.254.3.146 with netmask
For more information about the service processor, see "Service processor" on page 128.

2.12.3 High availability using the HMC

The HMC is an important hardware component. When in operation, POWER7
processor-based servers and their hosted partitions can continue to operate when no HMC is
available. However, in such conditions, certain operations cannot be performed, such as a
DLPAR reconfiguration, a partition migration using PowerVM Live Partition Mobility, or the
creation of a new partition. You might therefore decide to install two HMCs in a redundant
configuration so that one HMC is always operational, even when performing maintenance of
the other one, for example.
If redundant HMC function is desired, a server can be attached to two independent HMCs to
address availability requirements. Both HMCs must have the same level of Hardware
Management Console Licensed Machine Code Version 7 and installed fixes to manage
POWER7 processor-based servers or an environment with a mixture of POWER5,
POWER5+, POWER6, POWER6+, and POWER7 processor-based servers. The HMCs
provide a locking mechanism so that only one HMC at a time has write access to the service
processor. It is recommended that both HMCs are available on a public subnet to allow full
255.255.255.0.
255.255.255.0.
255.255.255.0.
255.255.255.0.
Chapter 2. Architecture and technical overview
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