There are multiples tasks involved in adop prepare, as a few examples below,
>> During the prepare phase, adop performs the following steps.
>> Checks whether to perform a cleanup, which will be needed if the user failed to
>> invoke cleanup after the cutover phase of a previous online patching cycle.
>> Validates system configuration to ensure that the system is ready to start an online patching cycle.
>> Checks to see if the database is prepared for online patching
>> Checks system configuration on each application tier node
>> Checks for the existence of the "Online Patching In Progress"
For more detailed reference, please refer, Oracle E-Business Suite Maintenance Guide Release 12.2
Hope this helps for a improved understanding.
Thanks Jibu and ALL,
I usually do not want to take my adop phase=prepare to take very long.
So it is better to complete all the cyles from previous patch
So that the next patching cylce will not run too long on "prepare"?
An execution of fs_clone will help to reduce time adop prepare if there were many patches applied in earlier patching cycle
But there is will be instruction if there is a fs_clone required to run
Hope this helps