How to P2V Multi-processor Servers to Uni-processor VMs

While troubleshooting poor performing VMs this week I was explaining to a customer the process of trying to downgrade the multi processor HAL of a Windows VM that was created by a P2V migration with VMware Converter. I ended up sending them a link to an older VMware Communities forum thread in which Mike Laverick of RTFM Education provides a quick how to guide. I also wrote (and sent the customer) a post earlier this year that offers similar advice, but P2V multi processor servers to single processor VMs instructs you to install a patch specifically for Windows Server 2003 VMs which then allows you to downgrade to a single processor.

The other difference worth mentioning between these two posts is the links to the Microsoft DevCon tool. Although VMware will not officially support using this tool on VMs, using this utility for forcing a HAL downgrade is possible when all else fails.

Check out the following instructions copied here and the various links in this post for more information.

VMware Communities: VC CPU - 97% and VM OS (Windows 2003) …

I’d back up your VM or make a new one from the template before attempting this. Changing the HAL can cause BSOD as you probably know…

How to downgrade the HAL:

Right-Click My Computer
Properties > Hardware Tab > Device Manager
Expand +Computer
Right-Click ACPI Multiprocessor
Choose Update Driver

From here Windows Dialogs vary - but whatever your version - you need to use

Install from a list or specific location (advanced)

then

Don’t search. I will choose a driver to install

You should then get the option to change the ACPI type

Some Windows OS (W2K3 if I remember rightly) doesn’t allow a GUI downgrade - but you can force one using MS DevCon utility .. [omitted]

You can the DevCon tool and documentation from here:

o Microsoft Help and Support:
http://support.microsoft.com/default.aspx?scid=kb;en-us;311272

o Microsoft Technet
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/TechRef/0f087656-fb2e-4828-9630-e76051a0a608.mspx

Tags: cpu, microsoft, P2V, virtualization, vmware converter, windows

This entry was posted on Wednesday, June 11th, 2008 at 6:11 am and is filed under P2V, converter, how to. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

David

The patch is only required on systems that don't have SP2 installed, which was released in March 2007.

mark

PlateSpin Migrate provides a configuration option that allows you to seamlessly modify the number of CPUs when configuring a migration job in the UI.

rbrambley

Mark,

Platespin Migrate looks like a great solution, but it costs $! In my experience VMware admins who already own VMware Converter (included with their VI 3.5 Enterprise licensing) are a tough sell for competition.

Mark

Hi Rich,

Cost is always releative to the effort ahead of you. For one-offs or a P2V here or a P2V there VMware converter works great - no dispute there.

PlateSpin can mititgate risk and reduce the manual effort in projects like these for just one example:

You have a virtual infrastructure upgrade (latest esx ver.) pending for 250 VMs. Processor (uni to multi) changes needed, resource pools are changing, memory allocation etc. for projects like these, there is a drastic amount of time savings involved when you pre-configure options like these. We are talking about reducing manual effort from weeks to days which is directly related to your planning effort and expierence level with PlateSpin...

Completing projects in ridiculously short timeframes is what you can enable if the right time is invested in learning about what options exist.

rbrambley

Mark,

No argument from me on using Platespin to drastically reduce the amount of time to complete the 250 example. Today PowerConvert is a better choice hands down for this scenario. VMware Converer 4 is coming soon however, and reducing the number of processors is a feature.

I'm sure you realize VMware Converter also can already be used from a centralized server today too, right?

Mark

VMconverter is indeed capable of running migrations “managed” from a central location. This is however only when performing a live migration…

Concurrent migrations are also possible.. but still somewhat limited, especially when you need to scaleout and run many migrations.

Also as the the complexity of the migrations comes into play (over WAN, biz critical app) here are some issues that could affect your ability to complete a smooth migration with VMconverter:

- Offline Migration -> needs boot CD

- No ServerSync; which facilitates certification testing(http://www.platespin.com/products/plateSpinMigrate/features.aspx)

- Error logging and job analysis is limited

...