Had an unusual question today from a user, who questioned why his VM became suspended. After a quick internal thought, because you probably clicked suspend, he advised that it occurred at 3am. So I open the VI Client logged on and lo and behold the VM was suspended. In addition it had happened the previous day as well.
Checking the user account (or not) that had performed this operation and found it was “User”. Yes User, not root, or a user account.
A quick scratch of the head and further investigation revealed that the VM was Windows 7. Windows 7 apparently, have not used it myself yet, default power management policy is to go into Standby after 20 mins of inactivity.
Anyways, why would a Guest O/S going into Standby actually put the VM into Suspended mode? Surely the VM itself would stay either Powered On or Powered Off.
No actually, in vCenter, in the VM Settings, on the Options tab in the Power Management option is a little radio button selection.
The option selected on this VM was Suspend the virtual machine
Checked another VM, this time Windows Server 2008 and the second option Put the guest OS into standby mode and leave the virtual machine powered on was selected.
The concept is fairly straight forward as it is simply replicating what happens on a physical device running Windows with a similar power management setting. Why this didn’t immediately occur to me? Well I guess doing virtualisation in the datacentre is primarily around server operating systems where this type of power management policy does not exist.
So easy to miss when in a different frame of mind.