HP-UX Virtual Partitions Administrator's Guide (includes A.04.06 and A.05.04)

• Software-related kernel panics
1
, 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