Db2 Virtualization; Db2 In An Aix Workload Partition - IBM Power7 Optimization And Tuning Manual

Furthermore, DB2 offers IBM SubCapacity Licensing, which enables customers to more
effectively consolidate their infrastructure and reduce their overall total cost of ownership
(TCO). DB2 also provides a flexible software licensing model that supports advanced
virtualization capabilities, such as shared processor pools, Micro-Partitioning, virtual
machines, and dynamic reallocation of resources. To support this type of licensing model, a
tool is provided that allows customers to track and manage their own software license usage.

8.4.1 DB2 virtualization

DB2 10.1 is engineered to take advantage of the many benefits of virtualization on POWER7
and therefore allows various types of workload to be deployed in a virtualized environment.
One key DB2 feature that enables workloads to run efficiently in virtualized environments is
STMM. STMM is designed to automatically adjust the values of several memory configuration
parameters in DB2. When enabled, it dynamically evaluates and redistributes available
memory resources among the buffer pools, lock memory, package cache, and sort memory to
maximize performance. The changes are applied dynamically and can simplify the task of
manual configuration of memory parameters. This feature is useful in a virtualized
environment because STMM can respond to dynamic changes in partition memory allocation.
By default, most DB2 parameters are set to automatic to enable STMM. As a preferred
practice, leave the instance_memory parameter and other memory parameters as automatic,
especially when you are running in a virtualized environment because DB2 is designed to
allow STMM to look for available memory in the system when instance_memory is set
to automatic.
DB2 also supports the PowerVM Live Partition Mobility (LPM) feature when virtual I/O is
configured. LPM allows an active database to be moved from a system with limited memory
to one with more memory without disrupting the operating system or applications. When
coupling dynamic LPAR (DLPAR) with STMM, the newly migrated database can automatically
adjust to the additional memory resource for better performance.
DB2 Virtualization, SG24-7805, describes in considerable detail the concept of DB2
virtualization, in addition to setup, configuration, and management of DB2 on IBM Power
Systems with PowerVM technology. That book follows many of the preferred practices for
Power virtualization and has a list of preferred practices for DB2 on PowerVM.

8.4.2 DB2 in an AIX workload partition

DB2 supports product installation on system WPARs. Since Version 9.7, the product can be
installed either within a local file system on a system WPAR or in a global environment under
either the /usr or /opt directory with each instance created on the local WPARs. In both
cases, each DB2 instance is only visible and managed by the system WPAR that it is created
in. If DB2 is installed in a global environment, different instances on different WPARs share
the globally installed DB2 copy to improve i-cache efficiency and memory usage. WPAR
mobility is also supported where a DB2 instance that is running on a system WPAR can
migrate to a remote WPAR on a different physical machine.
There are certain restrictions and considerations to keep in mind when you install DB2 in a
global environment:
Certain DB2 installation features cannot be installed on a system WPAR. These features
are IBM Tivoli® System Automation for Multiplatforms (SA MP) and IBM Data Studio
Administration Console.
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Chapter 8. DB2