I need to implement trusted SSL certificartes on some ESXi 5.1 hosts.
VMware KB 2015499 states that you have to put the host into maintenance mode. Is this really necesary? The only thing I can see that may cause an issue if the host is not in maintenence mode is restarting the management agents via the DCUI. However this has never been an issue with previous versions of ESXi as you have been able to restart the management agents without the host being in maitenance mode while VMs are running on the host with no impact to the running VMs.
Slightly relectant to perform this procedure without putting the host into maintenance mode on my customers production systems as the VMware KB states to put it into maintenance mode. However they are already overcommitting memory on each host in the cluster and therefore taking a host out for maintenance will make the situation worse.