rpms that require a service restart

[Robert Citek]

Greetings all,

I am in the process of upgrading a number of servers, all CentOS/RHEL.
Given a list of packages from 'yum check-update', I would like to
only install those packages that will not require a service restart.
Put another way, I would like to create an exclude list of all
packages that will require a service restart.

How can I find out which RPMs will require a service restart?

Regards,
- Robert