If you are running vSphere vCenter, you might have encountered the following error trying to modify virtual hardware (vDisk) on a VM directly from a host instead of doing it through vCenter :
Access to resource settings on the host is restricted to the server which is managing it
This behaviour is actually expected, some sort of lock is added to the VM configuration when hosts are joined to vCenter to avoid modification outside of vCenter. Of course, the proper way of doing it is performing this action through vCenter, however this might be necessary if the VM is the vCenter itself!
To temporarily workaround this issue, follow these easy steps :
1. Enable SSH on the host that currently hold this VM :
Configuration > Security Profile > Services > Properties > SSH > Options…
2. Login to the host using SSH.
3. Run the following command to stop the vCenter agent and restart the vCenter daemon :
/etc/init.d/vpxa stop /etc/init.d/hostd restart
NOTE : At this point, the vCenter reference has been removed from the host along with the lock.
4. Edit the ressource on your VM.
5. Start the vCenter Agent once you are done editing the VM :
/etc/init.d/vpxa start
6. Disable SSH on the host.
Configuration > Security Profile > Services > Properties > SSH > Options…