Benefits of logical partitioning

When you create logical partitions on your server, you can consolidate servers, share system resources, create mixed environments, and run integrated clusters.

The following scenarios illustrate the benefits of partitioning your server:

Consolidating servers

A logically partitioned server can reduce the number of servers that are needed within an enterprise. You can consolidate several servers into a single logically partitioned system. This eliminates the need for, and expense of, additional equipment.

Sharing resources

You can quickly and easily move hardware resources from one logical partition to another as needs change. Technologies such as the Micro-Partitioning® technology, allow for processor resources to be shared automatically among logical partitions that use a shared processor pool. Similarly, the PowerVM® Active Memory™ Sharing technology allows for memory resources to be shared automatically among logical partitions that use the shared memory pool. Other technologies, such as dynamic partitioning, allow for resources to be manually moved to, from, and between running logical partitions without shutting down or restarting the logical partitions.

Maintaining independent servers

Dedicating a portion of the resources (disk storage unit, processors, memory, and I/O devices) to a logical partition achieves logical isolation of software. If configured correctly, logical partitions also have some hardware fault tolerance. Batch and 5250 online transaction processing (OLTP) workloads, which might not run together on a single machine, can be isolated and run efficiently in separate partitions.

Creating a mixed production and test environment

You can create a combined production and test environment on the same server. The production logical partition can run your main business applications, and the test logical partition is used to test software. A failure in a test logical partition, while not necessarily planned, does not disrupt normal business operations.

Merging production and test environments

Partitioning enables separate logical partitions to be allocated for production and test servers, eliminating the need to purchase additional hardware and software. When testing has been completed, the resources allocated to the test logical partition can be returned to the production logical partition or elsewhere as required. As new projects are developed, they can be built and tested on the same hardware on which they are eventually deployed.

Running integrated clusters

Using high-availability application software, your partitioned server can run as an integrated cluster. You can use an integrated cluster to protect your server from most unscheduled failures within a logical partition.

Although there are many benefits to creating logical partitions, consider the following points before choosing to use logical partitions:

• Processor and memory failures might result in the failure of the entire server with all of its logical partitions. (The failure of a single I/O device affects only the logical partition to which the I/O device belongs.) To reduce the possibility of system failure, you can use the Advanced System Management Interface (ASMI) to set the server to unconfigure failing processors or memory modules automatically. After the server unconfigures the failing processor or memory module, the server continues running without using the unconfigured processor or memory module.
• Administering a consolidated system might be more difficult in some ways than administering multiple smaller systems, particularly if the resources in the consolidated system are used at a level close to their capacity. If you anticipate that you will use your server at a level close to its capacity, consider ordering a server model that is capable of Capacity on Demand (CoD).