/usr/lpp/diagnostics/bin/diagd is not running.

Problem:
/usr/lpp/diagnostics/bin/diagd is not running.

/etc/inittab Entry:
diagd:2:once:/usr/lpp/diagnostics/bin/diagd

Solution:
You can not make diagd continue to run. It has correctly determined that there are no periodic diags that should be run. So it exits cleanly freeing resources.
Periodic Diagnostics will run only on ses devices of a type container/sas/ses not container/sas/vses
The vses type devices do not have any diagnostics that should be run periodically. So there is no impact.