Installing and Managing HP-UX Virtual Partitions (includes A.04.01)

Introduction
What Is vPars?
Chapter 1
19
Why Use vPars?
The following explains some of the advantages of using vPars:
vPars Increases Server Utilization and Isolates OS and Application Faults
In certain environments one entire server is dedicated to a single application. When the 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 their now single OS has problems.
vPars provides a software-based solution that supports isolating OSs and their applications within virtual
partitions; thus, OS or application problems in one virtual partition do not affect OSs or applications running
in other partitions.
vPars also allows consolidation of underutilized servers into one faster server where applications may not be
permitted to affect one another, such as in the case of 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 and patch levels to run on the same server.
vPars Provides Flexibility Through Dynamic CPU Migration
vPars allows you to reassign CPUs from one virtual partition to another without rebooting.
Two virtual partitions that have different CPU utilization peak times can have processors moved between
them. For example, a transaction server used primarily during business hours could have CPUs reassigned
overnight to a report server. Such reassignments can be automated, for example, via cron.
Because vPars assigns specific hardware resources to specific virtual partitions, a user on the transaction
server at night is not affected by the reports server’s huge consumption of processing power. A virtual
partition uses only the CPUs that you assign to it; CPUs are not time-sliced across the virtual partitions.