Community developer blogs

John Howard

Recent Posts

• Hyper-V: How to remove disabled virtual network adapters from the parent partition

  Posted: 02 Jul 2009 at 01:01 by jhoward

  In May, I mentioned that we introduced a checkbox in the Hyper-V UI for Windows 7 and Windows Server 2008 R2 which determines whether a virtual NIC is created in the parent partition for External Virtual Networks. (To get a better understanding of Hyper-V networking and what this means, take a look at this article.

• New in Hyper-V Windows Server 2008 R2 Part 2 – MAC Spoofing

  Posted: 21 May 2009 at 18:29 by jhoward

  Our Virtual Switch got smarter in Windows Server 2008 R2. In Windows Server 2008, VMs are susceptible to MAC spoofing. MAC spoofing is where a (generally) malicious machine pretends to be another machine on a network (there are legitimate applications which do spoof MAC addresses though – Network Load Balancing being one such example). A MAC (Media Access Control) address in physical NICs is burnt in, although it can usually be over-ridden.

• Using Hyper-V Manager "v1" against Windows Server 2008 R2

  Posted: 06 May 2009 at 23:18 by jhoward

  I had a couple of emails overnight asking whether it is possible to use Hyper-V Manager "v1" (as in KB952627 for Windows Vista SP1, or part of RSAT in Windows Server 2008) pointing to a machine running Windows Server 2008 R2 RC or Microsoft Hyper-V Server 2008 RC. The short answer is yes, this works. The slightly longer (and intentionally non-exhaustive answer) is: Bug fixes in the "v2" UI are not in "v1" UI You won't have access to new features the "v2" UI exposes You may see a warning when ma

• Hyper-V RC Release Download Links

  Posted: 06 May 2009 at 02:41 by jhoward

  Today, the last of the download links for the Microsoft Hyper-V Server 2008 R2, Windows Server 2008 R2 RC (Release Candidate) release, Windows 7 client and the Remote Server Administration Tools (RSAT) for Windows 7 RC have gone live. Windows Server 2008 RC Download If you have an MSDN or Technet subscription, the download has already been live for a few days. As of today, you can also download directly. Follow this link and choose the "Download the RC now!" link at the top right o

• Hyper-V and in-place upgrade to Windows Server 2008 R2 Release Candidate

  Posted: 06 May 2009 at 01:08 by jhoward

  A cautionary note for those of you performing an in-place upgrade of a machine running Windows Server 2008 with the Hyper-V role enabled, to Windows Server 2008 R2 Release Candidate. During the installation, you will see the following compatibility report message stating that you should turn off the Hyper-V role: This warning is incorrect, and you should not do this as the virtual machines will not be present, and virtual network configuration will be lost once the role is re-enabled. You will

• New in Hyper-V Windows Server 2008 R2 Part 1 – Dedicated Networks

  Posted: 05 May 2009 at 01:43 by jhoward

  I thought I’d start a series of posts highlighting some of the smaller changes in Hyper-V in Windows Server 2008 R2. There’ll be plenty of people covering the larger features such as Live Migration, so I figured someone needs to cover the other fun stuff! Many of the improvements are not visible from an end use perspective – changes such as code cleanup, bug fixes, optimizations for performance and scalability. But many are visible, and this post covers one such change. I did a post back in June

• Hyper-V Security Guide available

  Posted: 01 Apr 2009 at 03:19 by jhoward

  The Hyper-V Security Guide is now available online or for download as a Word document. It covers hardening, delegation (including using SCVMM), and protection mechanisms for virtual machines. You can read it online here, or download the Word document(s) here. It even includes a link to HVRemote :) Cheers, John.

• Hyper-V KB967902 on Windows Update today

  Posted: 25 Mar 2009 at 05:22 by jhoward

  Just a quick heads up – as posted on our team blog earlier this month, KB967902 resolves an issue in Hyper-V regarding a certificate expiration issue. This was released earlier today on Windows Update. A restart will be required to complete the installation. Cheers, John.

• Hyper-V: Mouse Integration Components for SUSE available now

  Posted: 25 Mar 2009 at 04:51 by jhoward

  News just in – the VSC (Virtualization Service Client) component providing mouse integration for SUSE Linux Enterprise Server running as a guest operating system under Hyper-V has been released. The VSC is supported on SLES 10 SP2, x86 and x64 versions as virtual machines on systems running Hyper-V RTM or Windows Server 2008 R2 Beta. For more information on the licensing and download links, follow this link to Citrix Project Satori. Cheers, John.

• Understanding Microsoft Virtualization Solutions

  Posted: 24 Mar 2009 at 20:36 by jhoward

  OK, so I'm a couple of months behind the times.... but in case you aren't already aware, there's a free 400+ page Microsoft Press E-Book available online. It makes interesting reading and has an all-up view of Microsoft virtualization covering Hyper-V, System Centre Virtual Machine Manager, Application Virtualization, Desktop Virtualization and VDI. You can download the book from here. Cheers,John.

• Hyper-V Fixed VHD creation

  Posted: 24 Mar 2009 at 00:50 by jhoward

  As Ben mentioned last year, creating a large fixed size VHD in Hyper-V can be a lengthy operation as we zero out the contents of the file during the creation process. In Hyper-V itself, there is no workaround to this. However Chris, a developer on our team, has just posted up a utility called VHDTool which can create large fixed VHDs in seconds. If you are comfortable with the security implications of using such a tool and want large fixed VHDs created quickly, it could be an option for you. Th

• Hyper-V floppy trivia

  Posted: 22 Mar 2009 at 04:35 by jhoward

  "When I were a lad" (you have to say that in a northern British accent for authenticity), I used to catch the “Number 64” bus outside Fairfield Halls in Central Croydon as a leg of my journey to Junior school. The busses never arrived as scheduled some six or seven minutes apart during rush hour – instead, three of them nearly always arrived together. 1970’s London transport at it’s very best :). (Ask me about the “233 bus episode sometime – it has a different route these days, but ask only in

• Hyper-V energy drink

  Posted: 13 Feb 2009 at 23:33 by jhoward

  Just thought I'd add a quick blog entry - cool thing at the office today. Cans of Hyper-V ‘Pure Consolidated Energy for your Server’ turned up at our office this afternoon for the development team. Thank you marketing team! More info at www.serverunleashed.com   Cheers (literally!), John.

• Hyper-V Resolving Event ID 4096

  Posted: 28 Dec 2008 at 19:25 by jhoward

  Over the break I’ve been taking over Christmas, one of my goals was to move the remainder of my Virtual Server “production” VMs across to Hyper-V. But when nearing completion, I noticed that Server Manager was reporting a role error: Looking at the detail of the event logs, it was Event ID 4096 from Hyper-V-Config saying that The Virtual Machines Configuration {GUID} at ‘{Directory}’ is no longer accessible: The system cannot find the path specified. (0x80070003) This is a pretty common err

• How to detect UAC elevation from VBScript

  Posted: 19 Nov 2008 at 20:32

  While working on the next version of HVRemote yesterday evening, one of the things I wanted to address based on feedback from various people was to have the tool (written in VBScript) detect whether it is being run from an elevated command prompt. While this is relatively easy to determine using low

• Configure Hyper-V Remote Management in seconds

  Posted: 15 Nov 2008 at 00:02

  It has been a little quiet on the blog front, but sometimes, at least in this case, I hope I've come up with something worth waiting for. Announcing "HVRemote"...., a tool to "automagically" configure Hyper-V Remote Management. (Amazing what can be done with a few days vacation to kill before you lo

• How to use uniquely identify a virtual machine in Hyper-V

  Posted: 16 Sep 2008 at 23:13 by jhoward

  When managing a large number of virtual machines, there is often a need to tag it in some way with one or more properties uniquely identifying it for administrative purposes. One example would be to identify a virtual machine as belonging to a person, team or business unit. The Hyper-V WMI namespace

• Virtualization launch day

  Posted: 08 Sep 2008 at 21:30 by jhoward

  Today is (was) Virtualization Launch day. Although the keynote presentations were streamed live (in fact I'm just watching Bob Muglia finish up as I'm typing this), they will be available later this afternoon for on-demand viewing here. Some of the highlights: Microsoft Hyper-V Server is coming with

• Connection Manager Administration Kit for Vista

  Posted: 09 Aug 2008 at 18:34 by jhoward

  Curiosity got the better of me. When I was analyzing why Hyper-V Remote Management didn't always work over a VPN connection due to DNS the other day, I mentioned that I wasn't familiar with the replacement technology for CMAK in Windows Server 2003. Well, I found it (but it was surprisingly well hid

• Hyper-V: Eight useful links and tidbits for 08-08-08

  Posted: 08 Aug 2008 at 19:45 by jhoward

  I've had a few links I've been meaning to post up for some time now, so here's a small collection of eight of them on the 8th of the 8th, 08... WMI/Development using Hyper-V The WMI SDK for Hyper-V has recently been updated with code samples in C# and VBScript Want some WMI samples in Powershell? Tr