[ST OMU] Best procedure to downgrade an agent from v11.13 to v11.02 that is running NNMi server 9.20

[GTrejos7]

PROBLEM:


In an Operations Agent (OA) agent 11.13 that also is a NNMi server 9.20,
when trying to to downgrade from v11.13 to v11.02 in a NNMi server running V9.20 and
then launched the agent installation 11.02 however the installation fail, see below

INFO: Installing using the command (msiexec /i HPOvXpl.msi /quiet /L*vx+ "C:/Use
rs/A255232/AppData/Local/Temp/2//oainstaller.log"  REBOOT=ReallySuppress DEFER_A
CTIVATE="FALSE" DEFER_CONFIGURE="TRUE" PATCHACTIVATEONLY="FALSE" RUNACTIVATE="FA
LSE" RUNCONFIGURE="TRUE" )
ERROR: Installation of the component package HPOvXpl failed with error
(29754864)(Fatal error during installation.
).

HP Software cross platform component has detected that there is a newer version of the installation already installed.

The following steps were followed:

        1)  add/remove programs from the control panel
        2)  used cscript oainstall.vbs -r -a -v
        3)  used oasetup -remove -verbose



CAUSE:

It is not possible to downgrade the agent from 11.13 to 11.02 version on the system where NNMi is running.


SOLUTION:

It is not possible to downgrade the agent from 11.13 to 11.02 version on the system where NNMi is running.


1> The 11.13 agent patch version can be rolled to the 11.11.025 base agent version

2> Only the agent component ( HPOvOpsAgt ) can be removed from the system. However, the 11.11.025 Lcore ( SharedComponent ) component cannot be removed.  
If the command to remove the agent is executed, it removes only HPOvOpsAgt component and throws error during removal of HPSharedComponent packages.
The NNMi also consumes the HPSharedComponent and it is not possible to remove the 11.11.025 HPSharedComponent without affecting the NNMi.



This is documented in the following KCS document:

http://support.openview.hp.com/selfsolve/document/KM00912268