This document would be useful for anyone who is using Windows PowerShell to automate Hyper-V related tasks

http://www.microsoft.com/downloads/details.aspx?familyid=08A9EEB9-86FF-4A4F-8DFA-165BD701ABA9&displaylang=en

It’s a huge document, but worth using it as as reference.

By default we all (and should) use virtual hard drive (VHD) files to run virtual machines in a Hyper-V environment. But Hyper-V based virtual machines can also attach itself directly to physical disks (pass-through disks). Following are the factors to be considered before deciding to use pass-through disks.

• Studies have shown that VHD performance can be as high as 97% of native disk performance in terms off IOPS (http://www.qlogic.com/promos/products/hyper-v.aspx ). So the question is do you really need to use pass- through disks to achieve high performance or can you optimize the performance by following the best practices around VHD
• Pass-through disks do not support virtual machine snap shots, dynamically expanding hard disks and differencing hard disks
• A single VHD has a maximum capacity limit of 2TB.  Size of a pass-through disk can be bigger than this

Yet another awesome tool from the Sysinternals team, Disk2vhd. As the name implies this tool can covert a physical disk into a virtual disk. Here is the quick summary of it’s capabilities

• The converted VHD file can be used to boot from Virtual PC, Hyper-V and another physical machine as well
• Works on a machine that’s online
• VHD can be created on the same volume that is getting converted
• Preserves the partition information of the disk

For more details and download click here

I’m going to try this tool for backing up computer.

This is one of the FAQs in all my interactions with IT administrators. Here is the reason

As everyone knows 32 bit computers have a memory addressing limit of 4GB maximum. Since IT departments are looking at virtualization as a tool for consolidating multiple servers, this 4GB limit would not really help them. In order to achieve any meaningful consolidation of today’s and more importantly tomorrow’s workloads we need more than 4GB memory on Hyper-V enabled machines. Hence Microsoft decided to focus on x64 platform to develop and support Hyper-V.

Nevertheless there are scenarios where 32 bit hardware is available and need to be utilized. I suggest those customers to take advantage of Microsoft Virtual Server 2005 R2 SP1 

Windows Server 2008 R2 includes Hyper-V R2 and is available only in x64 edition. I moved my primary lab machine to WS2008 R2 and is really benefitting from these features

• I can create VHDs and mount them as drive letters using “Disk Management”. So I can add/remove files to VHDs without using virtual machines
• VHD files can now be added to virtual machines while they are running. So no need to shut down virtual machines if I want add more storage to it.
• Though I’m not using it very often “Live Migration” is the killer feature. This is a fitting reply to VMWare “vmotion” feature. It comes “free” with Windows server license. More importantly it works on almost any hardware and takes less than 15 minutes to configure.
• The “processor compatibility” feature is allowing me to perform “live migration” between computers with different processor numbers

I think this is significant. Microsoft has been working with Linux and other OSS communities for quite some time. But this is a major development towards Microsoft’s active participation with open source communities. Microsoft has released 20K lines of device driver code to Linux community. You can read the details here.

Hyper-V, Linux

Today, virtualization is a hot topic among IT Professionals. And it is not very difficult to find information on virtualization technologies. In fact every vendor has some story around virtualization. Information overflow and its unstructured nature is creating more confusion than clarity. This is exactly what we are trying to address in the virtualization track @ TechEd India 2009 ( www.msteched.in ). This track is going to have a complete 360 degree coverage of virtualization

There will be 8 dedicated sessions on virtualization ranging from desktop virtualization to data center virtualization. Here is a brief description of all these sessions

I plan to deliver at least a couple of sessions at TechEd India this time. One of them is going to be …

See you @ TechEd

Are you looking for ways to increase the size of virtual hard disk (VHD format) files? Then here is a great tool

http://vmtoolkit.com/files/folders/converters/entry87.aspx

Here is an excellent book on Virtualization available for free download from Microsoft Press.

http://csna01.libredigital.com/?urmvs17u33

The book is in PDF and has 452 pages, 15 MB approximately. The book contains detailed chapters on various virtualization technologies such as server, presentation, desktop & application.

If you want to know how reliable and scalable Hyper-V is, here is a quick list of Hyper-V statistics.

• 40% of www.microsoft.com runs on Hyper-V
• MSDN and TechNet web sites are completely running on Hyper-V
• Nearly 150 customers of Microsoft are using it in production as part of early adoption program
• Test figures have shown that I/O performance under Hyper-V is 90-97% of native performance
• Microsoft partner QLogic has achieved a throughput of 180,000 I/O per second for a storage device through Hyper-V

Of course there is more. This URL can give you more detailed information

There are few articles taking prowl in the Internet stating that Microsoft's Hyper-V is based on Xen's source code. This is not true and colleague has blogged about it here

VMRC Plus is a very cool and powerful tool for managing virtual machines running in a Microsoft Virtual Server environment. The following are some of the most important benefits of using VMRC Plus

• IIS and VMRC are not required
• Far better interface than IE based console for administration
• Manage multiple guest and host machines from the same console
• Supported on Microsoft Virtual Server 2005 R2 SP1
• It displays the disk, network, memory and CPU usage statistics nicely
• It FREE too!!!

You can download this tool from here.

The virtual machines running in a Microsoft Virtual Server instance shows that the virtual NIC operates @ 100Mbps even when the physical adapter is 1Gbps. But this indication is not correct. The virtual NIC is actually operating at 1Gbps.

Even for demo purpose I prefer Virtual Server than Virtual PC because of performance reasons. While running multiple virtual machines, virtual server gives better performance due to its multithreading capabilities.

In Microsoft Virtual Server and Microsoft Virtual PC we install "VM Additions" to improve the performance of the virtual machines and to enable time synchronization with the host machine. But VM Additions won't be there in Windows Server Virtualization (WSV). Instead, WSV is going to have something called "Integration Components". One of the features included in the Integration Components is the Virtualization Service Client (VSC) which I described in one of my earlier blog posts. Other features include time synchronization and heartbeat functionality.

Virtualization Service provider (VSP): This is the component of WSV which runs in the parent partition and directly communicates with the hardware drivers. VSP makes sure that the other virtual machines (child partitions) running in the same host can access the hardware successfully. It also ensures that the hardware access and sharing by multiple virtual machines is secure. For example VSP is responsible for sharing a common storage device across multiple virtual machines.

Virtualization Service Client (VSC): VSC runs in the child partitions and presents the virtual device to each child partition. For a given VSC there would be a corresponding VSP in the parent partition. In other words VSP and VSC exist as pairs. For example there would be a VSP/VSC pair for storage device.

VMBus: This is a point to point in memory bus and is used by VSP and VSC to communicate with each other

Often questions are asked about where the hardware drivers are loaded in Hyper-V. Some virtualization vendors load drivers in their hypervisor. But for improved security and reliability Windows do not load the divers onto Windows Hypervisor. Instead drivers are loaded onto the parent partition. These drivers are regular Windows drivers and do not require any customization for virtualization.

Microsoft is proving again that they are committed to interoperability in their products and solutions. The virtual server team will soon release the latest update (SP1) of their product, Virtual Server 2005 R2 . This release would officially support two new operating systems – Suse Linux 10 and Solaris 10 - as guests. Now Solaris would run as a window on my desktop. That's so cool, isn't it?

One of the reasons why I got so excited about my Toshiba Tecra M5 was that it supports hardware assisted virtualization. Virtual PC 2007 (VPC 2007) can take advantage of this feature and provide improved performance for virtual machines. So I started using VPC 2007 ever since the beta was launched. But I always found that the "Enable hardware-assisted virtualization" option is greyed out. Initially I thought that this could be a problem with the beta version of VPC 2007 and I just ignored it. Later when the full version got released I checked the same setting to see that it was still greyed out. Then I started suspecting the BIOS settings and found out that virtualization was not enabled thereL. As soon as I found this out, I enabled the same in the BIOS and went to check whether VPC 2007 was recognising it or not. But the option "Enable hardware-assisted virtualization" was still greyed out. I did not know what to do next. Finally I decided to ask few of my colleagues to see whether they were facing the same issue or not. Within minutes I got e-mail replies saying that this could be a BIOS problem. And finally I got suggested to upgrade the BIOS to version 3.20. I got thrilled and was damn sure that this solution would work. It was late in the night. But I couldn't resist. I started downloading the latest BIOS update (3.6MB) from Toshiba's web site using one of the slowest internet connections (Tata Indicom data card) available in the world today. I think it took half an hour for me to get the file downloaded on to my machine. I did not wait for even half a second to start the installation. But here comes the saddest moment in the entire story. My OS was 64 bit and the setup was supported only in 32 bit OSLLL. So there was no way I could upgrade my BIOS that night itself. I went to the bed in great despair. Today I am here in office to reinstall my laptop with a 32 bit Vista OS. But I finally I managed to upgrade my BIOS to version 3.20 and now I am in a state of nirvana because I can see the option "hardware assisted virtualization" enabled in VPC 2007.