What Is vPars?

vPars is a Virtual Partitions product that enables you to run multiple instances of HP-UX simultaneously on one hard partition by dividing that hard partition further into virtual partitions. Each virtual partition is assigned its own subset of hardware, runs a separate instance of HP-UX, and hosts its own set of applications. Because each instance of HP-UX is isolated from all other instances, vPars provides application and Operating System (OS) fault isolation. Each instance of HP-UX can have different patches and a different kernel.

Figure 1-1 vPars Conceptual Diagram

NOTE:

Definitions

This document uses the following definitions when discussing virtual partitions, nPartitions, and hard partitions:

A complex is the entire partitionable server, including both cabinets, all cells, I/O chassis, cables, and power and utility components.

A cabinet is the Superdome hardware “box”, which contains the cells, Guardian Service Processor (GSP), internal I/O chassis, I/O fans, cabinet fans, and power supplies. A complex has up to two cabinets.

Figure 1-2 Superdome Cabinet

A hard partition is any isolated hardware environment, such as an nPartition within a Superdome complex or an entire rp7400/N4000 server.

An nPartition is a subset of a complex that divides the complex into groups of cell boards where each group operates independently of other groups. An nPartition can run a single instance of HP-UX or be further divided into virtual partitions.

A virtual partition is a software partition of a hard partition that contains an instance of HP-UX. Though a hard partition can contain multiple virtual partitions, a virtual partition cannot span a hard partition boundary.

Product Features

A single hard partition can be divided into multiple virtual partitions.
Each virtual partition runs its own instance of HP-UX. Therefore, a single hard partition can contain multiple virtual partitions, and each virtual partition has a separate instance of HP-UX running different applications (or the same applications) at the same time without conflicts.
Each virtual partition is assigned its own resources (cores, memory, and I/O), so there are no resource conflicts between virtual partitions.
Virtual partitions can have different OS releases and patch levels.
Virtual partitions can be individually reconfigured and rebooted (for patches and other changes that require a reboot).
Users on one virtual partition cannot access files or file systems on other partitions unless the file systems are NFS-mounted, or access is otherwise given through networking or for cluster-aware volume groups used within ServiceGuard. Further, users configured on one virtual partition do not automatically have access on any other partition.
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.

^[1]Unless the vPars software product itself panics.

What Is vPars?

Technical documentation

» Table of Contents

» Glossary