Live application mobility

Both types of workload partitions, the system WPAR and the Application WPAR,
are capable of being configured to support mobility, or relocation.
The ability to move one WPAR from one LPAR to another, possibly from one
physical system to another, can be executed on active partitions. In this case the
application undergoes active relocation (it is hot-migrated), without stopping the
Note: In 2007, IBM’s System p6 and AIX 6 have 2 features that seem similar,
but are different: WPAR mobility & live partition mobility
– WPAR mobility, which is discussed in this book, is a feature of AIX 6 and
WPAR Manager. It is available on POWER4, POWER5, and POWER6
systems.
– Live partition mobility relies on the POWER6 hardware and hypervisor
technology (Advance Power Virtualization). It is available on POWER6
systems only. This feature is also available to AIX 5.3 LPARs.
7431CH_INTRODUCTION.fm Draft Document for Review August 6, 2007 12:52 pm
12 Workload Partitions in IBM AIX Version 6.1
application. The only visible effect for a user of the application is a slightly longer
response time while the application is migrating.
Workload partition mobility uses checkpoint & restart features to move workload
partitions. The checkpoint saves the current status of the application and then
restarts it on a new system or OS instance at the previously saved state.
Partition mobility is not a replacement for a High Availabilty solution. The premise
is to allow for planned migrations of workloads from one system to another while
the application is not interrupted. This could be the case for hardware
maintenance or a firmware installation on the server. The workload does not
need to be aware of the migration for the most part. But proper planning and
testing are always recommended before moving anything into a production
environment
Figure 1-4 depicts the use of WPAR relocation for workload balancing where two
applications are moved between two server to balance the load of these servers.
This figure also introduce the concept of WPAR manager that will be described in
Chapter 2, “Understanding and Planning for WPARs” on page 19.
Figure 1-4 WPAR migration
Important: Workload partition mobility is a software solution that is dependent
on AIX 6 for execution. When used for the migration of a WPAR from one
LPAR to another or between physical systems, then hardware and software
compatibility is required.