Here are some recomendations about how you should size VM memory :

You must size it to reasonably handle the expected load at ordinary and peak times because insufficient memory can significantly increase response times and CPU or I/O usage.

When running Windows in the child partition, you can use the following performance counters within a child partition to identify whether the child partition is experiencing memory pressure and is likely to perform better with a higher VM memory size:

Performance counter	Suggested threshold value
Memory – Standby Cache Reserve Bytes	Sum of Standby Cache Reserve Bytes and Free and Zero Page List Bytes should be 200 MB or more on systems with 1 GB, and 300 MB or more on systems with 2 GB or more of visible RAM.
Memory – Free & Zero Page List Bytes	Sum of Standby Cache Reserve Bytes and Free and Zero Page List Bytes should be 200 MB or more on systems with 1 GB, and 300 MB or more on systems with 2 GB or more of visible RAM.
Memory – Pages Input/Sec	Average over a 1-hour period is less than 10.

 

 

Correct Memory Sizing for Root Partition

The root partition must have sufficient memory to provide services such as I/O virtualization, snapshot, and management to support the child partitions. The root partition should have at least 512 MB available. Using Server Core in the root partition leaves additional memory for the VMs to use (approximately 80 MB for commit charge on 64-bit Windows).

A good standard for the memory overhead of each VM is 32 MB for the first 1 GB of virtual RAM plus another 8 MB for each additional GB of virtual RAM. This should be factored in the calculations of how many VMs to host on a physical server. The memory overhead varies depending on the actual load and amount of memory that is assigned to each VM.

 

 

 Patching and or Updating a Windows 2008/R2/Hyper-V Physical Host requires a close attention to the minimal details.

 Specially in production environment as we are talking not only to Microsoft patch/updates but also Industry products such as Lan cards drivers, Bios, Software Agents, firmwares, it’s important for you to remember that the updates are required only under certain circumstances ( e.g  updating you Network Lan Driver could let you to lose the Virtual Switchs Networks ).

 

Some recomendations :

 

1. Reduce/avoid some updates by using the Core Version. It’s my favorite version and not only because of this reason but also because it uses a lower resources translating in more CPU/memory to the VMs.

 

2. Only download updates that are available on Windows Update, as well those that are available at the Microsoft Download Center and Vendors Websites. NEVER, NEVER use DRIVERS/FIRMWARES from others sources. My recomendation is always go to the Vendor website to get the most updated driver/firmware. Don’t even think about downloading it from others sites/p2p networks. Why ? Simple, it could contain virus/worms and modified code.

 

2. PLAN : You might need a reboot of the Physical Production Host ( If you already implemented Live Migration, nothing to be worried : just move the VMs to another Hyper-V host . If not, it’s time for you to revise your downtime plan )

 

3.  Change the Windows Update Settings to Check for Updates and to let you choose which one is necessary.

 

 

Comprehensive list of Hyper-V R2 updates

 

Yes, that’s right, you can use the new Virtual Machine Servicing Tool 3.0 to automate and safely service offline virtual machines. Alsom this tool is FREE.

 

 

 

 

 

 

If you find these errors bellow in your System Event Logs, dont worry and IGNORE IT as they erroneous logged.  The drivers are in the correctly version and are functioning perfectly. These errors are reported because the Physical Host ( Hypervisor ) is running Windows 2008 and the guest machines are running Windows 2008 R2

 

Event Logs Errors to be igonored :

 

Log Name: System
Source: storvsp
Event ID: 5
Level: Error
Computer: 2008 R2 guest

Description: A storage device in ‘2008R2-Guest’ cannot load because it is incompatible with the server virtualization stack. Server version 2.0 Client version 4.2 . 

 

The parent partition uses a different VMBus version. You need to Install a matching VMBus version in this guest installation.
Log Name: System
Source: vmbus

Event ID: 2
Level: Error
Computer: 2008R2-Guest

Description: The parent partition uses a different VMBus version. You need to Install a matching VMBus version in this guest installation.

 

 

NIC driver on ‘2008R2-Guest’ cannot load because it is incompatible with the server virtualization stack.  Server version 2  Client version 196610 .

Log Name: System
Source: VMSMP
Event ID: 26
Level: Error
Computer: 2008R2-Guest

Description: NIC driver on ‘2008R2-Guest’ cannot load because it is incompatible with the server virtualization stack. Server version 2 Client version 196610 (VMID 9A5FAAC3-1F7A-442D-9525-46B39ACE22DB).

 

More info :http://support.microsoft.com/kb/972108/en-us

 

DON’T MISS IT : ONLY 70 participants per city : Melbourne, Sydney, Canberra, Brisbane, Perth, Adelaide. IT’S FREE.

 

Jeff Alexander and  Giovanni Marchetti will be running 2 day workshops where attendees can get all the latest updates on Hyper-V, System Centre Virtual Machine Manager, System Centre Operations Manager, System Centre Data Protection Manager.  Plus you’ll be able to get your hands dirty with labs on each technology.

 

There will be food provided and in each city we will be giving away a copy of the latest Hyper-V Resource Kit.

 

Event Overview

Two day workshop focused on Hyper-V and Microsoft Virtualization technologies.  The 2 day workshop will be a mixture of theory presentations and hands on labs.  Participants will walk away with a better understanding of Microsoft’s Virtualization technologies.

Agenda Topics

• Day 1
  • Virtualization 360 Overview
  • Evaluating the Environment & Planning:  MAP Tools and IPD Guides
  • MAP Lab
  • Hyper-V Architecture and Implementation – Hypervisor architecture, virtual disk and networks, security and licensing.
  • High Availability – 2008 R2 Clusters, Quick and Live Migration, Storage Implications
  • Lab:  Setup a 2-Node Hyper-V Cluster
• Day 2
  • System Centre Virtual Machine Manager 2008 R2 – Creating a Library, Physical to Virtual Migration, Optimal Placement
  • System Centre Operations Manager – Overview and integration with Virtual Machine Manager
  • System Centre Data Protection Manager – Overview and integration with Virtual Machine Manager
  • Architecture Considerations and Best Practices – Sizing Servers, storage and designing for high availability
  • Considerations on Dynamic IT – Integrating Hyper-V, SCVMM, SCOM with PowerShell to build a dynamic environment
  • Lab: Setup SCVMM and SCOM

Dates and Registration Details:

Melbourne Date: May 31st – June 1st Location:  Microsoft Melbourne Time: 9:00 – 5:00PM each day Registration:  Click Here to Register	Sydney Date: June 10th – June 11th Location – Microsoft Sydney Time: 9:00 – 5:00Pm each day Registration: Click Here to Register
Canberra Date: June 3rd – June 4th Location – Microsoft Canberra Time: 9:00 – 5:00PM each day Registration:  Click Here to Register	Perth Date: June 15th – June16th Location – Microsoft Perth Time:  9:00 – 5:00PM each day Registration: Click Here to Register
Brisbane Date: June 7th – June 8th Location – Microsoft Brisbane Time: 9:00 – 5:00PM each day Registration: Click Here to Register	Adelaide Date: June 21st – June 22nd Location – Microsoft Adelaide Time: 9:00 – 5:00Pm each day Registration: Click Here to Register