Support for 511 Disks on MPE/iX

by N. A. Narayanan
Commercial Systems Division

Introduction

Beginning with MPE/iX Release 6.5, it is possible to configure up to 511 spindles, an increase from the present limit of 255 disks.

Configuring More Than 255 Disks

The existing utilities volutil and mirvutil are used to configure more than 255 disks. There are no interface changes to these utilities to configure more than 255 disks.

However, it is not possible to configure more than 255 disks in a volume set. This was the same limit present in 6.0. HP recommends that customers use multiple volume sets when a large number of disks are installed on a single system.
Also, it is possible to configure 255 mirrored pairs (510 disks) in a mirrored volume set.

User Interface Changes

Sysgen has been modified to configure up to 511 disks in a device class. Until 6.5, sysgen could configure only up to 255 devices in a device class.
Utilities like volutil, mirvutil, dstat, discfree, etc. can display information related to more than 255 disks now.
Mirvutil can configure up to 255 mirrored pairs (510 disks) in a single mirrored volume set now.
Apart from the above, there are no changes in the interface of any of the utilities.

Forward/Backward Compatibility Issues

There are no compatibility issues between 6.5 and 6.0 or between 6.5 and 5.0/5.5. A system that has been installed with 6.5 can be back-dated to 6.0 without any problem, as long as it does not have more than 255 spindles configured. The same holds good for back-dating from 6.5 to 5.0/5.5.

Support for 511 Disks on MPE/iX

Technical documentation

» Table of Contents

» Index

Introduction

Configuring More Than 255 Disks

User Interface Changes

Forward/Backward Compatibility Issues