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[HDoaLC] Power Management

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One of the biggest challenges I have hit with using a Hyper-V virtual machine on my laptop as my desktop environment has been power management.  I was expecting this, as Hyper-V has been designed for servers and not for laptops.

The first issue I have encountered is battery life.  When running Windows 7 natively on my laptop – I can get about 2.5 hours on my battery.  When running Windows Server 2008 R2 + Hyper-V + Windows 7 in a virtual machine I can get about 1 hour and 10 minutes.

Ouch.

For the most part I have taken to carrying my power supply around with me (thankfully most Microsoft conference rooms have ample power outlets).

The next issue is related to the first.  Normally when Windows runs low on power it puts your laptop to sleep.  Unfortunately Hyper-V disables the ability to sleep.  As such I had to make some changes to the default power policy.  The first change was to configure Windows to shutdown when power got low instead of sleeping.  The second change was to raise the critical power warning from 7% to 12% – as my laptop needs to have enough time to shut down correctly.

One last issue that I have yet to find a solution for is the fact that when I am running the laptop in full screen mode, I do not get to see what the battery charge level is on my laptop – which means that it is always a surprise when the system shuts down from low power.  I have poked around and found that there are WMI interfaces that I could query over the network from the virtual machine that would allow me to see this information – but I have not had the time to actually try and put something together here.

Cheers,
Ben

Comments

  • Anonymous
    July 28, 2009
    I feel your pain :) I ran Server2008 + HyperV + Main workstation in a VM for a while when HyperV was initially released. The benifits were good, but the power problems soon forced me to abandon it. What me (and most of my company) is looking for is bare metal environment much like HyperV Server2008 or server core that has a basic UI for managing and viewing VMs. We want all the resources and power being given directly to the guests - if we are running a workstation VM then the parent partition is of little use to us and therefor all it needs to have is a UI to view/manage VMs. I raised this back in the HyperV TAP programme, but sadly nothing came of it. This could effectively be MS's client virtualisation solution to rival VMWareWorkstation - but would surely be more efficient. You guys need something because VirtualPC just doesn't cut it considering no x64 and no snapshot support. Lack of an appropriate client solution is surely harming the server side uptake of HyperV - I know it definately is in my company and I know others with the same issue. The fact that VMWare can move VMs from the client to the server with no conversions or such is a big win for them.

  • Anonymous
    July 28, 2009
    The comment has been removed

  • Anonymous
    July 29, 2009
    Hi "VMWare user" :) I think we misunderstand eachother, Citrix Xen Desktop and VMWare View are VDI solutions. We want to use our local  machines as the virtualisation hosts for "workstation" and "development" VMs. There is a lot of resource on 50 developer boxes each with quad core and 8GB ram. It is also a much simpler infrastructure. We want to see a bare metal HyperVisor that uses minimal resources itself and allows the VMs to use as much as possible. The only UI it needs is the ability to manage, view and use the VMs. A centralised VDI solution might be good for a virtualised desktop solution in larger houses, but what I'm looking for is the ability to allocate my resources to whatever I need at the time. If that involves shutting down my "workstation" VM to give extra resource to my "customer demo VM stack" then that is something that I want to be able to do :)

  • Anonymous
    August 03, 2009
    Ben, I've run into the same issue -- I run Server 08 x64 on my Dell "mobile workstation" laptop (16GB RAM/Quad/RAID). This machine functions as my "main" machine but it's very hard to use without power management -- I also find that multimedia playback on the parent is pointless. So I'm curious on what your take will be as to using Windows 7 virtual PC for this role of mobile test lab/demo. Mark

  • Anonymous
    August 06, 2009
    The comment has been removed