Relationships between patches are classified as function inheritance or incremental
relationships.
l Function inheritance
relationship: If the latest patch resolves all issues that have been resolved
in earlier patches, functions are inherited. Otherwise, functions are not
inherited.
l Incremental relationship: If
the latest patch can be directly installed on a device with earlier patches
installed, the relationship between patches is considered an incremental
relationship. Otherwise, the relationship between patches is considered a
non-incremental relationship.
Before installing an incremental patch, does not
remove the existing historical patch on a device, which prevents triggering
problems that have been resolved using the historical patch.
Before
installation a non-incremental patch, note the following issues:
l If a device needs to be
restarted or a software package needs to be upgraded, do not remove an existing
historical patch from a device. Set the latest patch as the patch to be loaded
at the next startup. After the device is restarted, the patch can take effect.
l If services keep running
on a device, remove an existing historical patch from a device and then install
the latest patch. During the historical patch removal and latest patch
installation, problems that have been resolved using the historical patch may be
triggered. Evaluate such risk before you operate the patches. Do not
perform any operations on the device between uninstalling the earlier patches
and installing the latest patch. Otherwise, services may be interrupted. For
example, saving configurations causes the commands added in the patches to be
lost.
For details about the incremental relationship between
patches, see "Relationship Between Patches" in the Patch Release
Notes.
