HP-UX 11i v3 Persistent DSF Migration Guide

hardware paths is provided via a More Info screen. Also, when Ignite-UX is used to cold-install a

system, HP-UX 11i v3 configures the boot, swap, and dump devices to use persistent DSFs.

Note: Ignite-UX also requires that legacy DSFs exist on the system.

Migrating to the Agile Naming Model

When HP-UX 11i v3 is installed, both legacy and persistent DSFs are created on the system. Both types of DSFs

can coexist and may be used simultaneously to access mass storage devices. However, only the use of

persistent DSFs allows the users to get the full benefits of the agile naming model. Therefore, HP recommends

users to migrate applications using legacy DSFs and hardware paths to the agile naming model.

This section defines the steps to migrate from using legacy DSFs to using persistent DSFs. In most cases, user

applications perform I/O through DSFs. In rare cases, they may reference hardware paths. Hardware paths

apply to various types of elements, such as cell, HBA, and device. If users have applications that reference such

hardware paths for devices beyond a mass storage HBA (legacy hardware paths), these hardware paths must

be migrated to the lunpath hardware paths as well.

Migrating legacy DSFs to persistent DSFs involves both preparation steps and migration steps.

Preparation

Preparation steps include identifying the applications and files that need to be migrated and saving original

copies of those files in case you need to back out the migration. To help with the identification, here are the

main changes that could affect an application:

 New DSF names and hardware path formats (see Formats of DSFs and Hardware Paths for Mass

Storage Devices)

 New DSF location (for instance, moved from /dev/[r]dsk to /dev/[r]disk)

 New command options to retrieve DSF names and hardware paths (for instance, add –N option to

ioscan)

 Decoding of DSF names and dev_ts is different as they no longer encode HBA/target/lun information

If you have written your own applications, look for the impacts above in the code.

Migration

Migration steps include making the actual modifications to the applications and files, testing the modified

applications, and finally disabling legacy naming model which removes the legacy DSFs. If the modified

applications run into issues, it might be necessary to back out the migration (return to using legacy DSFs) (see

Backing Out From Migration

section). The steps for migrating legacy DSFs to persistent DSFs are as follows:

Make an IUX Recovery Tape

Objective: Ensure the system can be recovered to the current state

Back up the system to a recovery tape. See the section “Backing Up Your System” in the Ignite-UX

Administration Guide available at

http://www.hp.com/go/sw-deployment-docs . Click on HP-UX Ignite-UX and

scroll down to the User guide section.

Identify System Configuration Files That Use Legacy DSFs/Hardware Paths