[CentOS] New to Centos and have question about updating packages

William L. Maltby wrote:
> Also, if a package that is currently running has been updated, or that
> package is currently using a package which has been updated and you want
> the currently running things to start using the new stuff _now_, you'll
> want to restart those packages. Until those packages end, disk space and
> ram memory is not finally freed.
>   

many service RPMs seem to do the restart automatically, I've noticed 
this with Postgres servers, at least.   of course, restarting a database 
server can interrupt any running processes that are using it...