HP OpenVMS Version 8.4 Upgrade and Installation Manual > Chapter 5 Preparing to Upgrade in an OpenVMS Cluster Environment
5.5 Types of Upgrades
Two types of cluster upgrades are available: a concurrent upgrade and a rolling upgrade. The type of upgrade you use depends on whether you want to maintain
the availability of the cluster during the upgrade and whether you
have more than one system disk. Review this chapter and then perform
the preliminary tasks for the upgrade procedure (concurrent or rolling)
that best suit your configuration. 5.5.1 Concurrent Upgrade |  |
This section describes the following: How a concurrent upgrade
works Preparing your system
for a concurrent upgrade
5.5.1.1 How a Concurrent Upgrade WorksDuring a concurrent upgrade, you must shut down
the entire cluster and upgrade each system disk. No one can use the
cluster until you upgrade each system disk and reboot each computer.
When the cluster reboots, each computer will run the upgraded version
of the OpenVMS operating system. If all systems in the OpenVMS Cluster environment
are booted from one system disk, you must perform a concurrent upgrade. 5.5.1.2 Preparing Your System for a Concurrent UpgradeTo prepare for a concurrent upgrade, follow these
steps: Log
in locally to the SYSTEM account. If you
have more than one system disk, make sure that you have performed
the preupgrade tasks on each system disk that you are upgrading.
Make sure the target system disk is not mounted on any other node
in the cluster and remains dismounted during the upgrade. It should
be mounted only on the system that is performing the upgrade. (For
information about dismounting disks, see Section 5.5.2.3.) Then go to Chapter 6 and perform
an upgrade on each system disk. You do not have to reboot the operating
system media for each upgrade. You only need to choose option 1 on
the menu for each upgrade. Shut
down all systems by entering the following command on each system
(satellite nodes first, then the boot nodes): When
the procedure asks whether an automatic system reboot should be performed,
enter N (NO). After all satellite nodes have shut down, select
the CLUSTER_SHUTDOWN option. When
the shutdown procedure is finished on all nodes, halt each system
by either pressing Ctrl/P or Halt. For more information about halting your Integrity
servers, see Section B.7.1. For information about halting your Alpha computer,
see Section A.3.1. If
you have only one system disk for your cluster, go to Chapter 6 to begin the
upgrade procedure. After the upgrade is
complete, you are instructed to reboot each computer in the OpenVMS
Cluster environment before beginning other postupgrade procedures.
5.5.2 Rolling Upgrade |  |
This section describes the following: How a rolling upgrade
works Preparing your system
for a rolling upgrade
5.5.2.1 How a Rolling Upgrade WorksA rolling upgrade allows
you to have a mixed-version cluster. During a rolling upgrade, you
keep some of the computers in the cluster running and available while
you upgrade others. You must have more than one system disk. You
upgrade each system disk individually, allowing old and new versions
of the operating system to run together in the same cluster. 5.5.2.2 Notes and RestrictionsThe following restrictions apply to rolling upgrades.
For additional compatibility issues and restrictions information,
see the HP OpenVMS Version 8.4 Release Notes. The system being upgraded
must not attempt to access any disk that is being accessed by one
or more of the remaining OpenVMS Cluster systems. HP recommends that all
Alpha computers in a cluster run the same (preferably the latest)
version of the OpenVMS Alpha operating system, and that all Integrity
servers run the same version of the OpenVMS Integrity servers operating
system. You cannot perform a rolling
upgrade if all systems boot from a single system disk. Perform a
concurrent upgrade instead. The upgrade procedure
affects the queuing system as follows: The queuing system is
not active on the system you are upgrading; do not attempt to execute
a START/QUEUE/MANAGER command. You cannot create a queue
database on the operating system CD/DVD (because it is not writable). The queue manager process
on other nodes in the cluster can continue to run during the upgrade
if the queue database is not on the disk being upgraded.
5.5.2.3 Preparing Your System for a Rolling UpgradeTo prepare for a rolling upgrade, follow these
steps: Log
in to any node where the target disk is mounted as a data disk rather
than as the system disk. (That disk must be the one on which you
already performed the preupgrade tasks described in Chapter 4.) Check the votes
and make adjustments to maintain the proper quorum so the cluster
can continue to operate throughout the upgrade. (HP OpenVMS
Cluster Systems describes this procedure in detail.) Use
the DCL command DISMOUNT/CLUSTER to dismount the data disk. (You
can also perform this operation using the SYSMAN utility.) Note that you can ignore messages from nodes where the
specified data disk is being used as the system disk. Verify
that the data disk has been dismounted successfully by entering the
following commands: $ MCR SYSMAN
SYSMAN> SET ENVIRONMENT/CLUSTER
SYSMAN> DO SHOW DEVICE disk-name |
Examine the display to be sure the disk is not
mounted on any nodes as a data disk. Noting the value listed in the
Trans Count field can help you make that determination: A value of
less than 50 indicates that the disk is mounted as a data disk rather
than as the system disk; a much larger value (for example, 300) indicates
that the disk most likely is the system disk. If
the disk is still mounted on any nodes as a data disk, use the SYSMAN
utility to dismount the disk; otherwise, exit the SYSMAN utility. Use the following
command to shut down any nodes that boot from the system disk you
are upgrading (shut down satellite nodes first): When
the procedure asks whether an automatic system reboot should be performed,
enter N (NO). After all satellite nodes have shut down, select
the REMOVE_NODE option.
If a proper quorum is not maintained at any time
during the upgrade procedure, the shutdown procedure hangs the cluster.
If the cluster hangs during a shutdown, you can use the Interrupt
Priority C (IPC) facility to adjust quorum from the system console
of a system that is still a cluster member. From an OpenVMS Alpha cluster member, press Ctrl/P. The IPC facility displays help
information about IPC commands. Enter the commands at the console: $ Ctrl/P
>>> D SIRR C
>>> C
Interrupt Priority C
Commands:
C device Cancel Mount Verification
Q Adjust Quorum
CTRL-Z Exit IPC
CTRL-P Prompt for Crash
IPC> Q
IPC> Ctrl/Z |
From an OpenVMS Integrity servers cluster member,
pressing Ctrl/P puts the system
directly into the IPC facility, which displays help information about
IPC commands. To adjust quorum, enter the commands shown in the following
example. Note that if systems are booted with XDELTA, pressing Ctrl/P brings the OpenVMS Integrity servers
system into XDELTA. The IPC facility is not available in this case. $ Ctrl/P
Interrupt Priority C
Commands:
C device Cancel Mount Verification
Q Adjust Quorum
CTRL-Z Exit IPC
CTRL-P Prompt for Crash
IPC> Q
IPC> Ctrl/Z |
You can also adjust quorum using Availability
Manager or DECamds. The method is equivalent to that used by IPC
except you do not have to use the console (this assumes the Data Analyzer
is running on a system outside the OpenVMS Cluster, which is recommended).
For more information, see the “Adjust Quorum” section
in the Availability Manager User’s Guide or the DECamds User’s Guide. The Availability Manager User’s Guide is available
at: http://www.hp.com/products/openvms/availabilitymanager After the shutdown procedure is finished on all
nodes, go to Chapter 6 to begin the upgrade procedure.
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