Introduction to Integrity Virtual Machines

Introduction
Today’s data centers frequently need to be flexible in meeting the demands of new customers and
new projects. Ideally, these demands are met quickly with minimal overhead while providing a
relatively high level of isolation from other customers. For most data centers, the best solution is one
that uses current capacity to satisfy these new demands while continuing to provide existing customers
with the precise capacity they expect. In doing so, data center owners can keep total cost of
ownership to a minimum while maintaining a high level of responsiveness to their customers.
To address this challenge, Hewlett-Packard has created the HP Virtual Server Environment, an
integrated server virtualization offering for HP Integrity and HP 9000 servers that provides a flexible
computing environment maximizing usage of your server resources. The Virtual Server Environment
encompasses a number of fully integrated, complementary components that enhance the functionality
and flexibility of your server environment including workload management, availability software,
utility pricing and partitioning. HP offers the broadest range of partitioning technologies, known as
the Partitioning Continuum, which includes hard partitions, soft partitions, and resource partitions.
This paper introduces HP Integrity Virtual Machines (Integrity VM) – an extension of the existing
Partitioning Continuum that blends and extends the benefits of HP-UX Virtual Partitions (vPars) and HP
Process Resource Manager (PRM). Virtual partitions allow you to create partitions to the granularity of
the hardware (CPU, I/O card) with each partition running its own version of an operating system.
This is a good approach when applications can utilize resources at the hardware granularity and the
applications should be isolated from one another for reliability or version compatibility of the software
stack. With PRM, you can create partitions at a granularity below that of the hardware component
with all applications running in one instance of an operating system. This is a good approach when
applications can cooperate within one instance of an operating system and utilize fractions of
hardware resources.
Integrity Virtual Machines combines both of these paradigms, providing a broader range of resource
allocation with application isolation. This addresses the situation where an application does not
require the full CPU or I/O card – therefore you would like to share hardware resources with another
application – but you want the applications in separate versions of an operating system. Conversely,
for applications that require more hardware resources, you can create virtual Symmetric
Multiprocessor (SMP) servers that deliver the power of multiple CPUs and I/O cards to the application
when it needs them.