based on different post from the forum - https://vox.veritas.com/t5/NetBackup/Completely-remove-host-certificates-in-8-1/td-p/844134 - is there any possibility in NetBackup 10.1.1 how to completely remove Host certificates for the servers that are no longer exist and are still located in the "Security Management -> Certificate Management"?
The goal is to remove over 3000 records that are absolutely irrelevant.
it seems it is not possible for security reasons. More detail is here: https://www.veritas.com/support/en_US/article.100041506.
Briefly said, NetBackup should remember undesired clients.
i agree with @Michal_Mikulik1.
If they are not causing any hinderance, just leave them to its fate. For a safety reasons you can Revoke those certificate so that no unauthorised connections made to master.
Hope it helps.