Upgrading the Operating System on a System Disk Shadow Set

It is important to upgrade the operating system at a time when your system can afford to have its shadowing support disabled. This is because you cannot upgrade to new versions of the OpenVMS operating system on a shadowed system disk. If you attempt to upgrade a system disk while it is an active member of a shadow set, the upgrade procedure fails.

Procedure for Upgrading Your Operating System

This procedure is divided into four parts:

Preparing a shadowed system disk for the upgrade.
Performing the upgrade.
Enabling volume shadowing on the upgraded system.
Booting other nodes in an OpenVMS Cluster system from the upgraded disk.

Preparing a Shadowed System Disk

On OpenVMS Cluster systems, choose the node on which you want to perform the upgrade.
Create a nonshadowed system disk to do the upgrade using either of these methods:
- Prepare a copy of the current system disk to use as the target of the upgrade procedure. See “Using Copy Operations to Create a Backup”.
- Use BACKUP to create a compressed copy of the shadow set on a single scratch disk (a disk with no useful data). See “Using BACKUP/IMAGE on a Shadow Set” for an example.
Enter the MOUNT/OVERRIDE=SHADOW_MEMBERSHIP command on the upgrade disk to zero the shadowing-specific information on the storage control block (SCB) of the disk. Do not mount the disk for systemwide or clusterwide access; omit the /SYSTEM and /CLUSTER qualifiers on the MOUNT command line.

Use the DCL command SET VOLUME/LABEL=volume-label device-spec [:] to change the label on the upgrade disk. (The SET VOLUME/LABEL command requires write access [W] to the index file on the volume. If you are not the volume owner, you must have either a system UIC or the SYSPRV privilege.) For OpenVMS Cluster systems, ensure that the volume label is a unique name across the cluster.

NOTE: If you have to change the volume label of a disk that is mounted across the cluster, be sure you change the label on all nodes in the OpenVMS Cluster system. For example, you could propagate the volume label change to all nodes in the cluster with one SYSMAN utility command, after you define the environment as the cluster:

SYSMAN>SET ENVIRONMENT/CLUSTER
SYSMAN>DO SET VOLUME/LABEL=new-label disk-device-name:

Ensure that the boot command line or file boots from the upgrade disk. The manner in which you store the boot command information depends on the processor on which you are working. For more information about storing boot commands, see the instructions in your hardware installation guide or the upgrade and installation manual for your Alpha computer.
If volume shadowing is enabled on the node, disable it according to the instructions in step 6. Otherwise, proceed to Performing the Upgrade .

Prepare to perform the upgrade procedure by disabling system disk shadowing (if it is enabled) on the node to be upgraded.




	NOTE: You cannot perform an upgrade on a shadowed system disk. If your system is set up to boot from a shadow set, you must disable shadowing the system disk before performing the upgrade. This requires changing SYSGEN parameter values interactively using the SYSGEN utility.

Invoke SYSGEN by entering the following command:

$RUN SYS$SYSTEM:SYSGEN

On OpenVMS Alpha systems, enter the following:

SYSGEN>USE upgrade-disk:[SYSn.SYSEXE]ALPHAVMSSYS.PAR
SYSGEN>

The USE command defines the system parameter file from which data is to be retrieved. You should replace the variable upgrade-disk with the name of the disk to be upgraded. For the variable n in [SYSn.SYSEXE], use the system root directory you want to boot from (this is generally the same root you booted from before you started the upgrade procedure).

Disable shadowing of the system disk by setting the SYSGEN parameter SHADOW_SYS_DISK to 0, as follows:

                 
SYSGEN>SET SHADOW_SYS_DISK 0

On OpenVMS Alpha systems, enter:

SYSGEN>WRITE upgrade-disk:[SYSn.SYSEXE]ALPHAVMSSYS.PAR

Type EXIT or press Ctrl/Z to exit the SYSGEN utility and return to the DCL command level.

You must also change parameters in the MODPARAMS.DAT file before shutting down the system. Changing parameters before shutdown ensures that the new system parameter values take effect when AUTOGEN reads the MODPARAMS.DAT file and reboots the nodes. Edit upgrade-disk:[SYSn:SYSEXE]MODPARAMS.DAT to set SHADOWING and SHADOW_SYS_DISK to 0.

Even if you plan to use the upgraded system disk to upgrade the operating system on other OpenVMS Cluster nodes, you should complete the upgrade on one node before altering parameters for other nodes. Proceed to Performing the Upgrade .

Performing the Upgrade

Boot from and perform the upgrade on the single, nonshadowed disk. Follow the upgrade procedure described in the OpenVMS upgrade and installation manual.
If you are upgrading a system that already has the volume shadowing software installed and licensed, then skip to Part 3.
Otherwise, you must register the Volume Shadowing for OpenVMS Product Authorization Key (PAK) or keys. PAK registration is described in the release notes and cover letter supplied with your installation kit.

Enabling Volume Shadowing on the Upgraded System

Once the upgrade is complete and the upgraded node has finished running AUTOGEN, you can enable shadowing for the upgraded node using the following steps.

Invoke the System Generation utility (SYSGEN) by entering the following command:
$RUN SYS$SYSTEM:SYSGEN SYSGEN>USE CURRENT SYSGEN>
The USE CURRENT command initializes the SYSGEN work area with the source information from the current system parameter file on disk. (To find out the current value of system parameters, use the SHOW command [for example, SHOW SHADOWING] to see the current system parameter values as well as the minimum, maximum, and default values of the parameters.)
To enable shadowing, set the system parameter SHADOWING to 2. If the system disk is to be a shadow set, set the system parameter SHADOW_SYS_DISK to 1, and set the SHADOW_SYS_UNIT parameter to the unit number of the virtual unit, as follows (assume the system disk virtual unit is DSA54):
SYSGEN>SET SHADOWING 2 SYSGEN>SET SHADOW_SYS_DISK 1 SYSGEN>SET SHADOW_SYS_UNIT 54 SYSGEN>WRITE CURRENT
Type EXIT or press Ctrl/Z to exit the SYSGEN utility and return to the DCL command level.
To ensure that volume shadowing is enabled each time AUTOGEN executes, edit the SYS$SYSTEM:MODPARAMS.DAT file to set the shadowing parameters. For OpenVMS Cluster systems, set system parameters in MODPARAMS.DAT on each node that uses volume shadowing. See Chapter 3 for more information about editing the MODPARAMS.DAT file.
Shut down the system on which you performed the upgrade, and reboot.

Booting Other Nodes in the OpenVMS Cluster System from the Upgraded Disk

If other nodes boot from the upgraded disk, the OpenVMS upgrade procedure automatically upgrades and runs AUTOGEN on each node when it is booted. The procedure for booting other nodes from the upgraded disk differs based on whether the upgraded disk has been made a shadow set.

If the upgraded disk is not yet a shadow set:
1. Disable shadowing (if it is enabled) for the system disk on the nodes to be upgraded.
2. Alter the boot files for those nodes so they boot from the upgraded disk.
3. Make sure the system parameters in the node-specific SYS$SYSTEM:MODPARAMS.DAT files are correct (as described in “Setting System Parameters ”). When the OpenVMS upgrade procedure invokes AUTOGEN, it uses these parameter settings.
4. Boot the nodes from the upgraded disk.
If the upgraded disk is already a shadow set member, additional steps are required:
1. For each node to be booted from the upgraded disk, edit ALPHAVMSSYS.PAR for Alpha systems and MODPARAMS.DAT to enable system disk shadowing. Set SHADOWING to 2, SHADOW_SYS_DISK to 1, and SHADOW_SYS_UNIT to the number of the system disk's virtual unit name. Remember to modify the files on the upgraded disk, not on the system disk, prior to upgrade.
2. On Alpha computers, you can use the SET BOOTDEF_DEV console command. For more information, see the hardware information or the upgrade and installation manual for your system.
Boot each node. With shadowing enabled in each node's ALPHAVMSSYS.PAR on the upgraded disk, the node can boot from the shadowed (upgraded) system disk.

Once you have successfully upgraded the system or systems and you have completed other postupgrade work (such as layered product installations), perform the following steps:

Mount additional shadow set members into the shadow set, if necessary. Do not use a command procedure to add members to a system disk shadow set. For more information, see “Booting from a System Disk Shadow Set”.
Back up your new system disk shadow set. If you usually use online BACKUP for this task, you can use one of the procedures described in “Performing Backup Operations on a Shadow Set”. If you usually use standalone BACKUP at this point, see “Restrictions on BACKUP Procedures”.