Doing IT Virtual

I’ve been waiting for a nice high-end quad-core laptop that can be used as a serious test machine for my Hyper-V work. Well, Dell came through with such a sweet discount that I did not have to wait any longer to order one of their new Precision M6400 with the Intel QX9300 2.53 GHz, 1067 MHz, with 12 MB of L2 cache. I should receive it by mid-December, and will be waiting anxiously for it. I chose it above the M4400 for it’s ability to expand to 16 GB of RAM, which I plan to configure as soon as the 4 GB chips become available within a reasonable price range.

If anyone has already started to work with one of these, I’d love to hear your experiences. When I have it up and running and beefed up with an extra disk and additional memory, I’ll post about it and how it performs running Hyper-V.

If you are interested in Hyper-V snapshots, check out the short video that I created for VirtualizationAdmin.com. In it I quickly run through how to create a snapshot, review the directory structure and files that are created, and show how to use the revert feature.

Check it out at http://virtualizationadmin.com/articles-tutorials/videos/microsoft-hyper-v-articles/general/using-hyper-v-snapshots.html.

If you have not found them yet, there is a series of five videos on the technet site that you might like to watch. These videos represent a set of interviews with several Windows Virtualization program managers that cover a range of topics including the Hyper-V architecture, high-availability, storage, snapshots, and so on. Here is a list of the video titles and URLs:

Hyper-V Part 1 - Architecture - Interview with PMs

Hyper-V Part 2 - VM Snapshots - Interviews with PMs

Hyper-V Part 3 - TAP and VSS Snapshots - Interview with PMs 

Hyper-V Part 4 - Disks and iSCSI - Interview with PMs

Hyper-V Part 5 - High Availability - Interview with PMs

Enjoy!

Quick update on the book - we encountered some delays, but about 1/3 of the book is now complete. The release date has been moved to April 2009. Here is the link: http://www.microsoft.com/MSPress/books/11842.aspx.

If there are any scenarios or information that you can't find, shoot me an email or post a comment with details. We have lots of content, but always looking for areas that are causing day-to-day problems or unanswered questions.

If you are interested in having a look at Live Migration coming in Windows Server 2008 R2 Hyper-V, take a look:

More short videos are available at http://www.microsoft.com/presspass/events/virtualization/default.mspx.

VirtualizationAdmin.com has posted Part I of my three part article that covers performing a server virtualization assessment with MAP 3.1. If you are interested in assessing your traditional infrastructure with the goal of developing a basic server virtualization plan, you should read this article.

In Part II and III to be posted in the near future, you will learn how MAP 3.1 (available for download from the Microsoft site) can assist you in your endeavors. I will post other entries when these are published on the VirtualizationAdmin.com site.

For those who took the Microsoft Beta Exam 71-652, check your MCP transcript or email to learn whether or not you passed the test. I received this email yesterday, and the result was posted today on the MCP site:

Thank you for taking beta exam 71-652: TS: Windows Server Virtualization, Configuring. We are writing to let you know that your results are being processed and are not yet available from Prometric or Microsoft.

The exam was released in its live form on August 25, 2008. Although, in general, we hope to make beta results available on or before the release of the live exam, delays or changes to the process are inherent in a beta. In this case, the processing of your individual scores was delayed beyond the exam release date, and we wanted to let you know the status of your scores to hopefully avoid any confusion or frustration on your part.

To learn more about the beta process, please visit: http://www.microsoft.com/learning/mcpexams/status/beta.mspx.

We anticipate that your scores will be available within a few weeks, but we are not able to provide an exact date. There is no action required on your part; your scores will be available at Prometric and on your Microsoft transcript as soon as our processing is complete. Thank you for your patience.

We sincerely appreciate the contribution you make as a beta tester in the Microsoft Certification program.

Regards,

The Microsoft Certification team

VirtualizationAdmin.com has posted my article on Integration Services. If you want to understand why you should install Integration Services in your guest OS, read this article. In it, I also review the installation process and the supported guest operating systems.

I have recently written an article for the VirtualizationAdmin.com site that reviews the basics of Hyper-V snapshots, the files associated with a snapshots, and how to use the snapshot Revert functionality. Check out the article and send any feedback/questions to me. I will be writing a follow-up article on using the snapshot Apply and Delete functionality in Hyper-V in the next few months.

I will be writing content for the TechGenix VirtualizationAdmin.com site. Chapter 7 of our Microsoft Virtual Server 2005 R2 Resource Kit is currently posted on the site at http://www.virtualizationadmin.com/articles-tutorials/general-virtualization-articles/microsoft-virtual-server-2005-r2-resource-kit-chapter7-practices-configuration-performance-tuning-.html.

I have a video and article on Hyper-V snapshots that will be posted soon and will provide an update to the link.

The book has been officially announced – here is the link: http://www.microsoft.com/MSPress/books/11842.aspx.

The publication date is planned for 12/17/2008.

AMD-Virtualization (AMD-V) provides a Secure Virtual Machine (SVM) processor architecture that allows software vendors to implement secure virtualization solutions and reduce software code complexity. Here are AMD-V SVM architecture highlights commonly mentioned with reference to virtualization software:

• Host Mode - allows a hypervisor, or more generically a Virtual Machine Monitor (VMM), to execute with the highest level of privilege. This execution mode is sometimes referred to as Ring -1 mode.
• Guest Mode - allows a guest operating system to execute in privileged-mode (Ring 0) and the application stack running in user-mode (Ring 3).
• Eight SVM instructions - support virtualization, including VMRUN which enables the context switch, or world switch, from Host Mode to Guest Mode to load and execute a new guest operating system.
• Virtual Memory Control Block (VMCB) data structure - contains guest state information, including settings that define intercepts and instructions that cause transitions from Guest Mode to Host Mode.
• Address Space Identifier (ASID) - a unique identifier assignment in a Translation-Lookaside Buffer (TLB) to distinguish between co-existing host and guest entries and help to improve the performance of a context switch. A TLB is a processor cache that holds virtual-to-physical memory address mappings. Each processor core has an individual TLB.
• Simultaneous support for 16-bit, 32-bit, and 64-bit guest operating systems.
• Rapid Virtualization Indexing or Nested Paging - provides processor-powered translation of the guest memory address space to the host virtual address space, and finally to the host physical address space.

The Rapid Virtualization Indexing feature of the AMD-V SVM architecture is not leveraged in the initial release of Hyper-V.

You can obtain in-depth information on AMD-V, from the AMD64 Architecture Tech Docs at http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_739_7044,00.html.

Intel Virtualization Technology (Intel VT) provides a processor architecture that supports virtualization software applications through a set of extensions referred to as Virtual Machine Extensions (VMX). Here are Intel VT VMX highlights commonly mentioned with reference to virtualization software:

• VMX Root operating mode - allows a hypervisor or VMM to execute in fully privileged mode.
• VMX Non-Root operating mode - allows a guest operating system to execute in Ring 0 and the application stack in Ring 3.
• Ten VMX instructions - support virtualization, including VMLAUNCH which enables the context switch to load and execute a new guest operating system.
• Virtual Memory Control Data Structure (VMCS) - contains guest and host state information, as well as VMX control fields used to manage the transitions between VMX Root and VMX Non-Root operating modes.
• Virtual Processor Identifier (VPID) - a unique identifier assignment stored in the VMCS to distinguish between co-existing host and guest entries. TLB entries are tagged with the appropriate VPID value, reducing the impact during context switches by not requiring a flush and reload of the TLB. Simultaneous support for 16-bit, 32-bit, and 64-bit guest operating systems.
• Extended Page Tables (EPT) - provide processor-powered translation of the guest physical memory address space to the host physical address space.

Like in the case of AMD-V Rapid Virtualization Indexing, Hyper-V does not leverage the Intel VT Extended Page Tables features in the initial release. Bottom line, Intel VT and AMD-V architectures offer much similar functionality to virtualization software application developers, although their feature implementation, nomenclature, and performance may differ from each other.

Here is a reference document from Intel on this topic: http://softwarecommunity.intel.com/isn/downloads/virtualization.pdf. You can also get more detailed information on the Intel VT from the Intel 64 and IA-32 Architectures Software Developer's Manuals at http://www.intel.com/products/processor/manuals/.

This blog has been quiet recently because of the holidays and pre-planning for the development of another Microsoft virtualization technology book. I am teaming up with Robert Larson of Microsoft Consulting Services, my co-author on the Microsoft Virtual Server 2005 R2 Resource Kit book, and Microsoft Press to publish the Microsoft Windows Server 2008 Hyper-V Resource Kit book. The book plan calls for publication in the 3rd quarter of CY 2008.

If you would like to give some feedback on book topics, please send us an email at vs2005r2rk@hotmail.com.

P.S. If you did not see the comment on the DoingITVirtual home page, our Microsoft Virtual Server 2005 R2 Resource Kit book just won a "Distinguished" award (the highest level) in the annual Puget Sound Society for Technical Communication competition. We hope that the more than 1400 individuals who downloaded the sample chapters and those of you who purchased the book have found it to be a good addition to your technical library.

Virtual Server 2005 R2 Resource Kit** This official Microsoft Resource Kit provides the in-depth technical guidance on installing, configuring, administering, and supporting Virtual Server 2005 R2 with Service Pack 1 (SP1) release. Buy it at Amazon.com or Barnes and Noble.

This post is content adapted from Chapter 11 of the Microsoft Virtual Server 2005 R2 Resource Kit.

Virtual Machine in Saved State Fails to Restart After a Change in Hardware-Assisted Virtualization State

If you enable hardware-assisted virtualization in your computer BIOS and try to start a virtual machine that was previously in a saved state, the virtual machine will not start up.

When hardware-assisted virtualization is enabled, Virtual Server internal data structures differ. Therefore, saved state files that are created when hardware-assisted virtualization is disabled cannot be used to restore a virtual machine after hardware-assisted virtualization is enabled.

Resolution

In this case, the only solution is to ensure that you shut down all virtual machines prior to switching the hardware-assisted virtualization setting in your computer BIOS.

Virtual Machine in Saved State Fails During Start Up on a Different Virtual Server Host

If you move a virtual machine that is in a saved state to another Virtual Server host, your virtual machine might fail at startup. Saved state files are not compatible when moving between different processor brands (Intel, AMD) or processor steppings (Intel Northwood, Intel Prescott).

Resolution

If you need to move a virtual machine to a Virtual Server host whose motherboard contains a different processor manufacturer or processor stepping than the originating Virtual Server host, you must completely shut down the virtual machine prior to moving the files.