"Sharing" a USB-connected UPS

[jonheal]

I have my APC UPS connected to a USB port. In OS X Energy Saver Preference Pane, I can configure the UPS to gracefully shutdown the machine when the battery is low.

I can do the same thing in Windows Power Options Properties in the virtual machine.

The problem is that as soon as Windows boots, the UPS options dissappear from OS X's Energy Saver Preference Pane. I'm not a hardware guy, but I can sort of imagine why this might be the case -- each device in the UPS bus only being able to service one environment using the bus, or something like that. But is there any way around this situation?

OS X is still "aware" of the UPS because it shows up in System Profiler, even when the virtual machine is running.

Message was edited by:

jonheal

[admin]

You'll have to decide whether you want OS X or Windows to talk to the UPS (I would think that OS X would be more useful, since it can shut down the entire machine, not just the VM) since only one OS can talk to a USB device at once. The UPS options probably disappear from the Energy Saver Preference because Windows is grabbing the device - you can stop this behavior by disconnecting the UPS from the guest.

[jonheal]

If OS X (via Energy Saver) sends a quit command to Fusion, will the VM suspend gracefully?

(I don't want to experiment, I'm anal about avoiding ungraceful shutdowns.)

[Pat_Lee]

By default, VMware Fusion will suspend the virtual machine when it is closed. Disable the confirmation dialog option in Preferences and I believe it will accomplish what you are looking for, but I haven't tested it.

Pat

[admin]

In addition to what Pat said, you can test this by making the appropriate changes, creating a new guest you don't care about, pulling the plug on the UPS, and watching to see if it suspends properly.

[bgertzfield · Accepted solution]

Actually, you're in luck.

You should \*not* configure the UPS to connect directly to Windows. Leave it connected to your Mac.

Instead, shut down your VM, then in the Virtual Machine -> Settings window, enable the Battery device.

This should make your Windows VM see a virtual battery whose levels correspond to the UPS attached to your Mac. You can then configure Windows to do whatever you'd like (shut down, etc.) when its battery gets low.

[jonheal]

Fantastic! Works great!

Fusion is steadily transforming itself from a faded bloom to the cat's meow.

And if I can think of any more hackneyed clichés to recycle, I'll use them in my next post.