Implementing a Virtual Server Environment: Getting Started

Chapter 3: Understanding the Choices for Virtualization
Technologies
This chapter describes the key benefits, trade-offs, and sweet spots for some of the HP virtualization
technologies. Understanding these will help you determine which technology is most appropriate for
solving a specific problem or achieving a certain benefit. Use this information as you decide on a
pilot project and assess the level of complexity and the amount of change that may be required to
implement them.
Note:
Most of the information in this chapter is taken from a book entitled The HP
Virtual Server Environment. For information about how to obtain this book,
see the last page of this paper.
Partitioning Solutions:
Why choose nPartitions (nPars)?
Key Benefits
• Hardware fault isolation (electrical).
• Operating system isolation.
• Choice of OS (HP-UX, Linux, Windows®, OpenVMS).
• No negative performance impact (in some cases you might see improved performance
resulting from less SMP overhead).
• Easy implementation.
• Dynamic cell OLAR (Online Addition and Removal) with HP-UX 11i v3.
Trade-offs
• Requires cell-based system.
• Granularity for a partition is at the cell level.
• No resource sharing across nPars (unless being flexed with Instant Capacity cores).
Sweet Spots
• Mission-critical applications that require fault isolation and dedicated resources.
• Need to run multiple operating systems on the same physical server.
• nPars are supported on both PA-RISC and HP Integrity servers.
• nPars can be a mix of PA-RISC and HP Integrity on Superdome servers (excellent for mixed
environments or during transitions).
Why choose Virtual Partitions (vPars)?
Key Benefits
• Dedicated hardware resources (processor, memory, I/O).
• Partition size can be scaled in increments of 1 processor core.
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