Technical data

Introduction
1.1 OpenVMS Releases
Minor releases are shipped to all customers with the appropriate software service
contracts.
1.1.4 OpenVMS Limited Hardware Release
Limited hardware releases are specific to, tested for, and targeted at new systems,
new option support, and new hardware configurations.
These releases may include specific remedial fixes that are required to support
the new hardware, but they do not include enhancements or general maintenance.
No application impact is expected. Full upward compatibility of user-mode code
is expected.
Limited hardware releases are ordered explicitly by customers and are not
automatically shipped to customers with software service contracts. A customer
receives the limited hardware release when they acquire new systems, new
options, or new configurations.
An example of a limited hardware release is OpenVMS Alpha Version 7.2-1H1 or
OpenVMS VAX Version 5.5-2H4.
1.2 Upgrade Paths
The following figures show the upgrade and rolling upgrade paths for OpenVMS
Alpha and OpenVMS VAX.
During a cluster rolling upgrade, you upgrade each system disk individually,
allowing old and new versions of the operating system to run together in the
same cluster. You must have more than one system disk. The systems that are
not being upgraded remain available.
During a concurrent upgrade, you must shut down the entire cluster and upgrade
each system disk. No one can use the cluster until you upgrade and reboot each
computer. Once you reboot, each computer will be running the upgraded version
of the operating system.
The bold lines in Figure 1–1 and Figure 1–2 indicate direct supported upgrade
paths to Version 7.3. All other lines indicate supported upgrade paths, some for
prior versions.
1–2 Introduction