HP UX Patch Management Patch dependencies, Types of dependencies, Corequisites and prerequisites

Patch dependencies

A patch that depends on other software in order to install or run correctly is said to have a dependency on that other software. In order to become fully active, a patch might require changes to areas of the system other than those it modifies. Such a patch might have a documented dependency on one or more patches or nonpatch software products that are responsible for the changes in these other areas.

For example, in Figure 3-3: “Patch Supersession Chains and Patch Dependencies” (page 31), PHXX_31967 and PHXX_31937 depend on each other (mutual dependency). At a later time, PHXX_32384 supersedes PHXX_31937, and PHXX_31967 can be successfully installed with either patch. (PHXX_32384, as a cumulative patch, will satisfy the entire dependency.)

Figure 3-3 Patch Supersession Chains and Patch Dependencies

However, a superseded (older) patch does not satisfy a dependency on a superseding (newer) patch. Figure 3-3: “Patch Supersession Chains and Patch Dependencies” (page 31) provides an example. PHXX_33662 supersedes PHXX_31967, but PHXX_33662 has an updated dependency on the superseding patch PHXX_32384. In this case, the older patch (PHXX_31937) doesn't satisfy the new dependency

For more information about supersession, see “Ancestors and supersession” (page 25).

Types of dependencies

HP provides patch dependency information for a patch in its patch details page and its patch text file. The dependency information is contained in the following fields:

•Patch Dependencies

Patches that are required for proper operation.

•Other Dependencies

Various dependencies that cannot be described as patch dependencies, such as those that are needed only under specific circumstances.

NOTE: While looking at a patch details page or a patch text file, you might notice an additional field that is dependency related. The Hardware Dependencies field represents a different type of dependency than those presented in this section. It does not show dependencies on other patches, but rather gives specific system models to which a patch is limited.

Corequisites and prerequisites

A corequisite fileset must be available for installation to start and must be present when installation is complete. No installation ordering is predictable.

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