They were updated from 4.0.6 using yum update. They are plain CentOS 7.3 hosts

So I have used now on both hosts the command

sudo yum install collectd collectd-disk collectd-netlink collectd-virt collectd-write_http fluentd rubygem-fluent-plugin-rewrite-tag-filter rubygem-fluent-plugin-secure-forward
 

I see that collectd is set to disabled. Is it ok or other necessary actions to be taken?

Do I need to restart any components on hosts or engine after install of those packages on hosts?

Where should I have noticed wrong data because of not having the packages in 4.1? The bugzilla contains the words "metrics store solution" and seems something evolving in a future feature... not already in...

Thanks,

Gianluca