Migrating from HP-UX 11i v1 Virtual Partitions to a Mixed HP-UX Version Environment

Introduction

Virtual Partitions (vPars) is a software solution available on HP 9000 and HP Integrity cell-based

servers running HP-UX 11i. It allows a system administrator to “carve up” a single nPartition

(hardware partition) into multiple independent entities, each owning processors, memory, and I/O

resources. This is accomplished through a software layer called the vPars monitor which resides

between the operating system kernel and the firmware. The vPars monitor controls the ownership of

the processors, memory, and I/O resources on the system. Each virtual partition must have its own

copy of the operating system, thereby providing namespace and software fault isolation.

Companies running vPars on HP-UX 11i v1 (B.11.11) wanting to upgrade to a later version of the

operating system face the task of refreshing their environments without destabilizing their production

workloads. This is a particular concern because HP has now shipped HP-UX 11i v3 (B.11.31), and

those who seek stability may wish to skip HP-UX 11i v2 (B.11.23) in favor of the newer, faster

product which will be supported far longer. New multi-OS version support was introduced with vPars

A.05.03, which allows users to keep some of their virtual partitions running HP-UX 11i v1, while

trying out HP-UX 11i v2 or 11i v3 in others. This paper presents two ways an administrator can

upgrade a subset of the virtual partitions in an nPartition with minimal impact on the remaining virtual

partitions. It also discusses the limitations of the process and those situations where it will not work.

This document is a guide for system administrators who plan to upgrade a subset of their virtual

partitions to a newer version of the HP-UX operating system. While the main emphasis of the

document is to help those who are still running HP-UX 11i v1, all of the concepts and a subset of the

steps are also applicable to those who are currently running HP-UX 11i v2.

Migration Process Overview

Migrating to virtual partitions with mixed OS versions greatly increases flexibility, but requires

substantially more planning than upgrading all of the virtual partitions at the same time. This problem

is exacerbated by the large number of changes introduced by HP-UX 11i v3 (See the HP-UX 11i

Version 3 Release Notes, available at http://docs.hp.com). With careful planning and attention to

detail, it is possible to minimize the amount of interruption to those virtual partitions which are not

being upgraded at this time. Without this planning, it is almost inevitable to have unnecessary

downtime.

Migration Restrictions

Please read through this section before attempting to upgrade your nPartition to a vPars environment

with mixed HP-UX 11i versions. Your environment must comply with all of the requirements in the

following list:

• You must be on a supported system: rp7405, rp7410, rp7420, rp7440, rp8400, rp8420,

rp8440, or Superdome

• The system must be updatable to or at supported firmware levels; see

http://docs.hp.com/en/oshpux11iv3.html#System%20Firmware

• The system must have or will switch to supported peripherals

• There must be have enough disk space for root file systems

• You must make sure you will be able/allowed to reboot production virtual partitions

Migration Strategies

There are two general strategies for upgrading:

• Update (less downtime for virtual partitions that are not impacted by the upgrade)

• Cold migration (more downtime)