Windows 2008 Power Schemes and Performance Impact

What is a Power Plan ?

A power plan is a collection of hardware and system settings that manage how your computer uses power. You can use power plans to reduce the amount of power your computer uses, maximize performance, or balance e two.

Power plans available with Windows Server 2008 are Balanced , Power Saver & High performance.

In Microsoft Windows 2008  &  Windows 2008 R2 Operating Systems , the default Power Scheme is set to be as Balanced which gives a balance between Performance and Energy Savings.

Doing some research on the impact of Power Scheme on Performance of Windows 2008 Hosts and specifically Hyper-V Hosts led me to multiple articles that has been referred below. Interestingly there is a well documented Microsoft Knowledge base article as well that you can find here. Although the KB does not say how much of an impact can the change have , there are some bloggers who have shared their testing result on the same.

Changing default power scheme from “Balanced” to “High Performance” has yielded 22% improvements in SQL performance that has documented by Glen out  here and Improvements in Hyper-V Performance can be found here. In our preliminary testing , we are seeing better results for Performance of  Hyper-V hosts that has been changed from default “Balanced” Power Scheme to “High Performance” Power scheme.

For people who are interested in Changing the Power scheme -

In a Full Installation of Windows Server 2008 , Open Control Panel –> Power options and you will be bale to select the Power Scheme of your choice

In a Core install of Windows Server 2008 , One can make use of powercfg.exe command to change the power scheme.

” powercfg -getactivescheme ” would dispplay the active Power Scheme in the Host

“ powercfg -setactive 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c ” use this command to set the Power Scheme to High Performance

We are still doing our round of  testing to validate the improvements in Performance of Hyper-V hosts and Windows 2008 hosts due to Power Scheme. Would love to your experience and feedback as well.

Microsoft Hyper-V vs. VMware ESX

This is not just another post to compare VMware ESX with Microsoft Hyper-V since i certainly believe without any doubt at this moment VMware ESX is leaps ahead of other competing hypervisors including Microsoft Hyper-V. What Microsoft has done with Sp1 for Windows 2008 R2 is introduce couple of cool features in Dynamic Memory and Remote FX to Hyper-V but these are not game changers. In this post , I am just trying to portray the  advantages and short comings of both ESX and Hyper-V.

What works for VMware ESX ?

• Virtual Center, the management console of VMware for managing multiple ESX Servers generally does not get the credit it deserves. A single management console for managing , monitoring and patching of ESX hosts and the Guest VMs and it’s Applications makes administrator’s work easier.
• Ability to configure Customized roles for administrators in Virtual Center.
• Huge list of supported of Guest Operating Systems
• Memory Management features such as TPS , Ballooning , Swapping and Memory compression.
• HA & DRS Clustering capability of ESX is technologically superior to Microsoft’s Hyper-V Cluster giving the ability to provide high availability to VMs and at the same time distributing loads evenly across the hosts.
• Fault Tolerance capability of VMware ESX
• Third party plugin support from various vendors like EMC , NetApp , f5 , Dell etc.. that helps administrators manage them from Virtual Center
• Advanced technologies like Storage vMotion , Storage IO Control , Network IO Control , Host Profiles and DPM ( Distributed Power Management)
• VAAI (vStorage API for Array Integration)  helps offload the load of Storage related task on to Storage Array’s
• Whole community of bloggers and lots and lots of free tools for VMware environment
• VMware KB – Knowledge base site of VMware that is constantly updated and contains step by step resolution for most of the issues on VMware environment.
• Stability/Resiliency of ESX

What VMware ESX lacks ?

• There is no single management console for managing multiple free ESXi Servers. This can be achieved for Hyper-V using Hyper-V Manager..
• Cost – Costlier when compared to Hyper-V but one has to consider the amount of features that comes packed with ESX which makes ESX worth every penny spent !!

What works for Microsoft Hyper-V ?

• Microsoft recommends Hyper-V as part of their solutions and tight integration and support with various other products of the Microsoft Eco-system helps in adoption of Hyper-V.
• Hyper-V Manager that helps in managing multiple Hyper-V Servers from a single console . Please note that there is limited functionality but still one can manage multiple Hyper-V Servers from a single console.
• Cost ( Hyper-V is part of Windows 2008 family of products) – If the Virtual machines that run on Hyper-V are based on Windows , the cost associated with Hyper-V goes down dramatically since in a VMware environment we have to account the OS cost of VM’s as well.

What Hyper-V lacks ?

• Dependency on multiple applications for managing ( SCVMM) , monitoring ( SCOM) and patching (SCCM/WSUS) of Hyper-V hosts and VMs and also the fact that there is no tight integration between these components.
• Lack of Customizable roles for Administrators in Hyper-V Manager and SCVMM
• Resiliency/Stability of Hyper-V cannot match that of ESX
• Lack of advanced technologies supported by ESX like Storage vMotion , SIOC , NIOC , VAAI etc…

These are my personal opinion of what works for the hypervisors and what they lack ? Would love to hear your comments as well.

Post P2V Tasks

P2V does not end with migrating a Physical Server to Virtual Server  but there are certain post P2V tasks that could help in improving the performance of the converted server. 

• Ensure you install VMware Tools on the migrated VM without fail.
• Remove all unwanted hardware components from a migrated virtual server like serial ports and floppy drives.
• Change the CPU and memory of the VM as per requirement and do not go with default values as they reflect the resources as in the Physical Server.
• Physical Servers are installed with OEM drivers which are resource consuming and these drivers can be removed using Add/Remove Programs once they have been converted to VMs.

I came across a HP utility that can be download from here  which can be used to remove HP PSP with a single click.

One of the issue that is reported is the error when they get when try to assign IP to the migrated server -  ” The IP address XXX.XXX.XXX.XXX…” is already assigned to another adapter”.

This error message is caused by Ghosted NIC Cards that are present. These are the NIC cards that are converted as part of the P2V process since they were part of the physical Server but does not show up on the device manager. Follow the below mentioned steps to uninstall the ghost NIC cards.

• Click Start –>Run–>Cmd [ Open a Command prompt]
• Type in “set devmgr_show_nonpresent_devices=1″ [ This change would display all non-present devices in device manager]
• From the command prompt, type in “devmgmt.msc” [Do not go to Run prompt to open device manager or open from a GUI since above change would be effective from cmd prompt only]

            

• Click View –>Show Hidden Devices
• Non-Present devices are grayed out and can be uninstalled from the server. In this case  out NIC cards has to be uninstalled.

             

• Now try assigning the IP back to the NIC card in the Virtual Server and should work fine.

IP Address issue has been addressed by Microsot here and VMware here and lot of other bloggers too.