Often times a mongod server is improperly set up. Some we see from the warnings on Cloud/Ops Manager, but some we do not (e.g. filesystem not using XFS). A lot of these settings require sudo privilege, which Automation Agent is lack of. Unfortunately, in order to correct improper setup requires a server restart, or worse, data migration. I'd suggest making mdiag an official tool, and run it as an optional pre-requisite on production machines. Having a beautiful table output is a huge plus.