Today i have found a limitation using host profiles and this together with a vmkernel port that has Mtu 9000 activated. maybe it has not been a requirement when designing the host profiles?
We set up the reference host with 4 vmkernel ports, one for management, one for vmotion, one for FT and one for NFS. The port that we wanted to use Jumbo frames for was the vmotion port.
As i wrote in an earlier post, I used the powerCLI to configure the Mtu for the actual vmkernel port Get-VmhostNetworkAdapter -Name vmk1 | Set-VmhostNetworkAdapter -Mtu 9000.
Then i add this host as an reference host in the Host Profiles and attach it to the cluster. Adding a new host and then Apply profile, creates all our vmkernel ports correctly but when checking what Mtu the vmotion vmkernel port got, it is created with the default Mtu of 1500. This is not so good because i do not want to use several different ways to configure and i want to be able to trust the Host Profiles solution. The only vmkernel port that was created before applying host profiles was the management port so it has nothing to do with editing exisiting. So the result is that i need to after applying a host profile, run a powerCLI command to edit the Mtu.
Strangely no matter if the Mtu is 9000 or 1500 the hosts are compliant in the GUI..
This applies to vSphere 4.1 u1 (i do not know how this behaves in vSphere 5)
Conclusion of this is that I have to think a bit more about using the Host profiles. If it is not fully implemented then it is not usable to get uniform hosts.