PHSS_27875.X11-RUN-CL PHSS_28681.X11-RUN-CL,fa=HP-UX_B.11.11_32/64 PHSS_27875.X11-TCH-B-MSG PHSS_28681.X11-TCH-B-MSG,fa=HP-UX_B.11.11_32/64

You can also show the filesets that a given patch has superseded. These superseded filesets will be listed whether or not they are installed on a system. This is done by using the swlist command to list the supersedes attribute of the patch. Note that the first patch of any particular patch supersession chain does not have a supersedes attribute. In the following example, patch PHSS_28681 is shown to supersede patches PHSS_27875, PHSS_26498, and PHSS_25201. (The output has been reformatted to improve readability.)

swlist -llevel -aattributepatch_id

For example:

$ swlist -l fileset -a supersedes PHSS_28681

#Initializing...

#Contacting target "some_system"...

#Target: some_system:/

#

# PHSS_28681

PHSS_28681.X11-JPN-S-MSG PHSS_27875.X11-JPN-S-MSG,fr=* PHSS_26498.X11-JPN-S-MSG,fr=* PHSS_28681.X11-RUN-CL PHSS_27875.X11-RUN-CL,fr=* PHSS_26498.X11-RUN-CL,fr=* PHSS_25201.X11-RUN-CL,fr=* PHSS_28681.X11-TCH-B-MSG PHSS_27875.X11-TCH-B-MSG,fr=* PHSS_26498.X11-TCH-B-MSG,fr=*

Advanced topic: supersession and the patch_state attribute

When a superseding patch is applied to a system, the superseded patch (if there was one) remains on the system but is not active. Only the top patch of the chain is in the active (applied) state. For more information about patch state, see “Patch state” (page 19).

You can use the following swlist command to show the patch_state attribute for patch patch_id:

swlist -a patch_state -x show_superseded_patches=true patch_id

It is important to note that the availability of a newer, superseding patch does not preclude the use of the older patch. Depending on the circumstances, a superseded patch might be a better choice than the patch superseding it. Older patches have had more exposure to varied, real-world use. When they have been shown to induce no ill effects, they are generally safer than newer patches that supersede them. Thus, if two patches in a supersession chain solve the problem you are facing, you might find that the older patch is the better choice.

Because HP-UX patches are cumulative, a superseding patch negates the need for the previous patch. As an example, patch PHSS_29377 delivers all the features and fixes of all other patches shown in Figure 3-2:“HP-UX Patch Supersession Chain” (page 29). This patch will also satisfy any dependencies on all patches in the supersession chain.

SD-UX does not allow you to install a patch that has been superseded by another patch already installed on a system. Using Figure 3-2:“HP-UX Patch Supersession Chain” (page 29) as an example, if you have patch PHSS_29377 installed on a system SD-UX will not allow you to install patch PHSS_29323.

Patch supersession chains can be more complex than the one shown in Figure 3-2:“HP-UX Patch Supersession Chain” (page 29).

28 HP-UX patch overview