HP-UX Virtual Partitions Administrator Guide (includes A.05.07) (5900-1229, September 2010)

• Software-related kernel panics

, resource exhaustion failures, and reboots in one virtual

partition do not affect any other virtual partition.

• Processing resources and memory available at boot time can be added to or removed from

a virtual partition without rebooting.

Why Use vPars?

The following are some of the advantages of using vPars. Note that some of these features, such

as dynamic memory migration, are only available in more recent releases.

vPars Increases Server Utilization and Isolates OS and Application Faults

In certain environments, one entire server is dedicated to a single application. When demand

for that application is not at peak, such as during non-business hours, the server is underutilized.

If many servers are configured this way, you have many servers that are being underutilized.

You can minimize investment and operational costs by consolidating servers and running multiple

applications on one server; however, this leaves all applications vulnerable to problems if any

one application or its single OS has problems.

vPars provides a software-based solution that supports isolating an OS and its applications

within virtual partitions; thus, OS or application problems in one virtual partition do not affect

the OS or applications running in other partitions.

vPars also allows consolidation of underutilized servers into one faster server where applications

are not permitted to affect one another, such as an ISP running many small e-services application

servers.

vPars Provides Flexibility Through Multiple but Independent OS Instances

vPars offers flexibility by allowing different HP-UX instances, OS Releases, and patch levels to

run on the same server.

vPars Provides Flexibility Through Dynamic Processing Core and Memory Migration

vPars enables you to reassign processing resources and memory from one virtual partition to

another without rebooting.

Processing cores and memory can be moved between two virtual partitions that have different

resource utilization peak times. For example, a transaction server used primarily during business

hours can have a portion of its cores and memory reassigned overnight to a report server. Such

reassignments can be automated, for example, via a cron job.

Because vPars assigns specific hardware resources to specific virtual partitions, a user on the

transaction server at night is not affected by the processing power consumption of a report server.

A virtual partition uses only the cores and memory that you assign to it; cores are not time-sliced

across virtual partitions.

Supported Environments

This section has been moved to the HP-UX Virtual Partitions Ordering and Configuration Guide,

which is available at:

http://docs.hp.com/en/vse.html#Virtual%20Partitions

HP Product Interaction

• Processor Terminology Processing resources under vPars, both as input arguments and

command outputs, are described as “CPUs.” For multi-core processors such as the PA-8800

and dual-core Intel Itanium processors, the term “CPU” is synonymous with “core.” The

term “processor” refers to the hardware component that plugs into a processor socket.

1. Unless the vPars software product itself panics.

Supported Environments 19