Windows Server 2008 R2 release candidate: what’s new? (part 2)

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Windows Server 2008 R2 logoA couple of weeks back, I wrote about some of the new features in Windows Server 2008 R2 but I did say that was only part 1 as there were a few surprises in store (held back for discussion at TechEd this week):

  • First up, Hyper-V R2 will support 64 logical CPUs. At release, Hyper-V was supported for up to 4 CPUs each with 4 cores, then Intel released it’s Dunnington 6-core chips and a hotfix was released for 24 core support (see Microsoft knowledge base article 956710). Originally the R2 release was going to support 32 cores but performance testing went well, so today Microsoft will announce support for 64 logical cores. What this means is that Hyper-V hosts can achieve better density levels and run more virtual machines with multiple virtual CPUs, improving the platform’s ability to scale in line with hardware developments.
  • Secondly, there is a new feature in Hyper-V R2 called processor compatibility mode. Sharp-eyed users of the Windows Server 2008 R2 release candidate may have noticed a new checkbox labelled migrate to a physical computer with a different processor version. Configured on a per-VM basis, this allows virtual machines to be migrated between hosts using CPUs from different processor families (from the same vendor – this is Intel-Intel and AMD-AMD, not AMD-Intel or vice versa), providing greater flexibility when expanding clusters with new hardware, by abstracting virtual machine down to the lowest possible denominator in terms of available instruction set.
  • Finally, there will be a new feature in Windows Server 2008 R2 called file classification infrastructure (FCI). Nir Ben Zvi is a Senior Program Manager working on Windows Server at Microsoft and he explained to me that customers are struggling with increasing risks and costs as they balance data management needs with data management tools. With the new FCI functionality, Microsoft sees customers classifying their data and applying a policy according to the classification, so that it may be treated differently according to the user requesting access. Classification runs on a schedule and can even detect patterns of text in a scanned document. Stale files can be expired (moved to an administrator-controlled directory, with expiry notified in advance). Documents may be watermarked. And, it should be no surprise that FCI supports integration with SharePoint as well extensibility by partners.

If Windows Server 2008 was good, R2 is looking better. The release candidate is available now, with general availability expected in the second half of 2009 (although not confirmed by Microsoft on any official sites).

More on SCDPM and agent placement in a virtualised environment

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Earlier this week, I wrote an introduction to System Center Data Protection Manager (SCDPM). In that post, I mentioned that SCDPM 2007 SP1 supports Virtual Server 2005 R2 and Hyper-V virtualisation platforms but I’d like to elaborate on that and highlight the need to consider where best to deploy the SCDPM agents.

With SCDPM 2007 SP1, we can back up Windows and non-Windows guest operating systems on either Virtual Server 2005 R2, Windows Server 2008 with the Hyper-V role enabled, or Hyper-V Server 2008. Depending upon the guest operating system, it will either be a VSS capable or a non-VSS capable guest .

Linux, Windows NT, Windows 2000, Oracle and line of business applications will generally be non-VSS capable and in this case SCDPM will:

  1. Hibernate the virtual machine to secure the memory and CPU contents to a saved state.
  2. Take a snapshot of the virtual machine using the volume shadow copy service (VSS) – this takes just a few seconds (as the backup is taken from the snapshot, not the offline virtual machine).
  3. Resume the virtual machine.
  4. Use block level checksums to send only the changes within the VHDs (since the last backup) to the SCDPM server.

On a VSS capable guest operating system.

  1. SCDPM contacts the VSS writer on the virtualisation host to request protection from the SCDPM agent, in the form of a referential VSS copy.
  2. A query is performed via the integration components to instructs the VSS writer in the guest operating system (e.g. SQL Server VSS writer, Exchange Server VSS writer, Windows Server VSS writer) to create a consistent snapshot.
  3. Only when the guest data is consistent and clean does the virtualisation layer provide SCDPM with a copy to backup from the host.

This referential VSS writer process means that:

  • There is no downtime (backups are performed online).
  • The use of recursive VSS ensures consistency without hibernation.
  • The only guest requirement is the presence of VM additions/integration components.
  • Guests are protected from the host.

Virtual Server exposes the backup options for VSS and non-VSS capable as online or offline backup. Hyper-V is more descriptive, with Backup using Child Partition snapshot (the equivalent of an online backup) or Backup Using Saved State if there are no integration components available

So, with no downtime and no agent deployment for each guest operating system, why wouldn’t we always protect virtual machines from the host? Well, when we protect the guest from the host, the whole virtual machine is treated as a logical unit without any data selectability or granularity. Whilst there are some advantages to this approach (it allows bare metal recovery of virtual machines to any other host; the whole virtual machine set can be protected with a single SCDPM agent and a single DPML license; non-Window or legacy Windows operating systems can be backed up), if an agent is deployed within the guest then SCDPM can select the data to protect/recover – e.g. individual SQL databases, Exchange storage groups, file sets, Sharepoint farms, etc.) but with the additional cost of deploying and licensing agents.

We can also use a hybrid of the two models – running an agent inside critical virtual machines but only using host-based backups for non-VSS cpabable operating systems. Indeed, it may even be desirable to protect the entire virtual machine and its data separately (e.g. if using passthrough disks then the guest operating system cab be backed up via the host and the data protected via the guest).

SCDPM 2007 SP1 will back up shares, volumes, system state and any VSS-aware application workloads (subject to licensing options – an Enterprise Data Protection Management License will be required for native backup and recovery of applications). On the licensing front, it’s also worth considering the Server Management Suite Enterprise (SMSE) as it includes management licenses for System Center Data Protection Manager, Operations Manager, Configuration Manager and Virtual Machine Manager with free usage rights up to the number of guests licensed with each host operating system edition (one for Windows Server 2008 Standard Edition, four for Windows Server 2008 Enterprise Edition and unlimited for Windows Server 2008 Datacenter Edition).

The key points for agent placement are application consistency and the granularity of restoration required. By deploying an agent inside a virtual machine, a VSS-aware application will be signalled that a snapshot is about to be taken and consistency can be guaranteed. Alternatively, if application consistency is not an issue, by installing the agent on the host, each virtual machine can be backed up as a single container – in effect the virtual machine will be consistent but the application may not be.

Great tool for resizing virtual hard disks

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Over the weekend, I wanted to build a guest VM quickly to show the effects of having the Integration Components installed (cf. one without) so I downloaded a Windows Vista Evaluation virtual machines from the Microsoft VHD Test Drive programme.

Unfortunately the supplied VHD only had 3GB of free disk space, so I couldn’t apply SP1 in order to install the Hyper-V integration components and, even though it was a dynamically expanding VHD, it had a maximum size set of 16GB.

VHD ResizerThat’s when I stumbled across a great tool for resizing virtual hard disk files – VHD Resizer (formerly VHD Expander). After telling it the source and destination file names, then leaving it to work it’s magic for a while, I attached the new (larger) VHD to my VM, expanded the volume in Disk Manager and was greeted with extra hard disk space.

This tool is definitely one to remember.

Microsoft Virtualization: the R2 wave

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

The fourth Microsoft Virtualisation User Group (MVUG) meeting took place last night and Microsoft’s Matt McSpirit presented a session on the R2 wave of virtualisation products. I’ve written previously about some of the things to expect in Windows Server 2008 R2 but Matt’s presentation was specifically related to virtualisation and there are some cool things to look forward to.

Hyper-V in Windows Server 2008 R2

At last night’s event, Matt asked the UK User Group what they saw as the main limitations in the original Hyper-V release and the four main ones were:

  • USB device support
  • Dynamic memory management (ballooning)
  • Live Migration
  • 1 VM per storage LUN

Hyper-V R2 does not address all of these (regardless of feedback, the product group is still unconvinced about the need for USB device support… and dynamic memory was pulled from the beta – it’s unclear whether it will make it back in before release) but live migration is in and Windows finally gets a clustered file system in the 2008 R2 release.

So, starting out with clustering – a few points to note:

  • For the easiest support path, look for cluster solutions on the Windows Server Catalog that have been validated by Microsoft’s Failover Cluster Configuration Program (FCCP).
  • FCCP solutions are recommended by Microsoft but are not strictly required for support – as long as all the components (i.e. server and SAN) are certified for Windows Server 2008 – a failover clustering validation report will still be required though – FCCP provides another level of confidence.
  • When looking at cluster storage, fibre channel (FC) and iSCSI are the dominant SAN technologies. With 10Gbps Ethernet coming onstream, iSCSI looked ready to race ahead and has the advantage of using standard Ethernet hardware (which is why Dell bought EqualLogic and HP bought LeftHand Networks) but then Fibre Channel over Ethernet came onstream, which is potentially even faster (as outlined in a recent RunAs Radio podcast).

With a failover cluster, Hyper-V has always been able to offer high availability for unplanned outages – just as VMware do with their HA product (although Windows Server 2008 Enterprise or Datacenter Editions were required – Standard Edition does not include failover clustering).

For planned outages, quick migration offered the ability to pause a virtual machine and move it to another Hyper-V host but there was one significant downside of this. Because Microsoft didn’t have a clustered file system, each storage LUN could only be owned by one cluster node at a time (a “shared nothing” model). If several VMs were on the same LUN, all of them needed to be managed as a group so that they could be paused, the connectivity failed over, and then restarted, which slowed down transfer times and limited flexibility. The recommendation was for 1 LUN per VM and this doesn’t scale well with tens, hundreds, or thousands of virtual machines although it does offer one advantage as there is no contention for disk access. Third party clustered file system solutions are available for Windows (e.g. Sanbolic Melio FS) but, as Rakesh Malhotra explains on his blog, these products have their limitations too.

Windows Server 2008 R2 Hyper-V can now provide Live Migration for planned failovers – so Microsoft finally has an alternative to VMware VMotion (at no additional cost). This is made possible because of the new clustered shared volume (CSV) feature with IO fault tolerance (dynamic IO) overcomes the limitations with the shared nothing model and allows up to 256TB per LUN, running on NTFS with no need for third party products. The VM is still stored on a shared storage volume and at the time of failover, memory is scanned for dirty pages whilst still running on the source cluster node. Using an iterative process of scanning memory for dirty pages and transferring them to the target node, the memory contents are transferred (over a dedicated network link) until there are so few that the last few pages may be sent and control passed to the target node in fraction of a second with no discernible downtime (including ARP table updates to maintain network connectivity).

Allowing multiple cluster nodes to access a shared LUN is as simple as marking the LUN as a CSV in the Failover Clustering MMC snap-in. Each node has a consistent namespace for LUNS so as many VMs as required my be stored on a CSV as need (although all nodes must use the same letter for the system drive – e.g. C:). Each CSV appears as an NTFS mount point, e.g. C:\ClusterStorage\Volume1
and even though the volume is only mounted on one node, distributed file access is co-ordinated through another node so that the VM can perform direct IO. Dynamic IO ensures that, if the SAN (or Ethernet) connection fails then IO is re-routed accordingly and if the owning node fails then volume ownership is redirected accordingly. CSV is based on two assumptions (that data read/write requests far outnumber metadata access/modification requests; and that concurrent multi-node cached access to files is not needed for files such as VHDs) and is optimised for Hyper-V.

At a technical level, CSVs:

  • Are implemented as a file system mini-filter driver, pinning files to prevent block allocation movement and tracking the logical-to-physical mapping information on a per-file basis, using this to perform direct reads/writes.
  • Enable all nodes to perform high performance direct reads/writes to all clustered storage and read/write IO performance to a volume is the same from any node.
  • Use SMB v2 connections for all namespace and file metadata operations (e.g. to create, open, delete or extend a file).
  • Need:
    • No special hardware requirements.
    • No special application requirements.
    • No file type restrictions.
    • No directory structure or depth limitations.
    • No special agents or additional installations.
    • No proprietary file system (using the well established NTFS).

Live migration and clustered storage are major improvements but other new features for Hyper-V R2 include:

  • 32 logical processor (core) support, up from 16 at RTM and 24 with a hotfix (to support 6-core CPUs) so that Hyper-V will now support up to 4 8-core CPUs (and I would expect this to be increased as multi-core CPUs continue to develop).
  • Core parking to allow more intelligent use of processor cores – putting them into a low power suspend state if the workload allows (configurable via group policy).
  • The ability to hot add/remove storage so that additional VHDs or pass through disks may be assigned to to running VMs if the guest OS supports supports the Hyper-V SCSI controller (which should cover most recent operating systems but not Windows XP 32-bit or 2000).
  • Second Level Address Translation (SLAT) to make use of new virtualisation technologies from Intel (Intel VT extended page tables) and AMD (AMD-V nested paging) – more details on these technologies can be found in Johan De Gelas’s hardware virtualisation article at AnandTech.
  • Boot from VHD – allowing virtual hard disks to be deployed to virtual or or physical machines.
  • Network improvements (jumbo frames to allow larger Ethernet frames and TCP offload for on-NIC TCP/IP processing).

Hyper-V Server

So that’s covered the Hyper-V role in Windows Server 2008 R2 but what about its baby brother – Hyper-V Server 2008 R2? The good news is that Hyper-V Server 2008 R2 will have the same capabilities as Hyper-V in Windows Server 2008 R2 Enterprise Edition (previously it was based on Standard Edition) to allow access to up to 1TB of memory, 32 logical cores, hot addition/removal of storage, and failover clustering (with clustered shared volumes and live migration). It’s also free, and requires no dedicated management product although it does need to be managed using the RSAT tools for Windows Server 2008 R2 of Windows 7 (Microsoft’s advice is never to manage an uplevel operating system from a downlevel client).

With all that for free, why would you buy Windows Server 2008 R2 as a virtualisation host? The answer is that Hyper-V Server does not include licenses for guest operating systems as Windows Server 2008 Standard, Enterprise and Datacenter Editions do; it is intended for running non-Windows workloads in a heterogeneous datacentre standardised on Microsoft virtualisation technologies.

Management

The final piece of the puzzle is management:

There are a couple of caveats to note: the SCVMM 2008 R2 features mentioned are in the beta – more can be expected at final release; and, based on previous experience when Hyper-V RTMed, there may be some incompatibilities between the beta of SCVMM and the release candidate of Windows Server Hyper-V R2 (expected to ship soon).

SCVMM 2008 R2 is not a free upgrade – but most customers will have purchased it as part of the Server Management Suite Enterprise (SMSE) and so will benefit from the two years of software assurance included within the SMSE pricing model.

Wrap-up

That’s about it for the R2 wave of Microsoft Virtualization – for the datacentre at least – but there’s a lot of improvements in the upcoming release. Sure, there are things that are missing (memory ballooning may not a good idea for server consolidation but it will be needed for any kind of scalability with VDI – and using RDP as a workaround for USB device support doesn’t always cut it) and I’m sure there will be a lot of noise about how VMware can do more with vSphere but, as I’ve said previously, VMware costs more too – and I’d rather have most of the functionality at a much lower price point (unless one or more of those extra features will make a significant difference to the business case). Of course there are other factors too – like maturity in the market – but Hyper-V is not far off its first anniversary and, other than a couple of networking issues on guests (which were fixed) I’ve not heard anyone complaining about it.

I’ll write more about Windows 7 and Windows Server 2008 R2 virtualisation options (i.e. client and server) as soon as I can but, based on a page which briefly appeared on the Microsoft website, the release candidate for is expected to ship next month and, after reading Paul Thurrott’s post about a forthcoming Windows 7 announcement, I have a theory (and that’s all it is right now) as to what a couple of the Windows 7 surprises may be…

Microsoft Virtualization User Group meeting: April 2009

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

The Microsoft Virtualization User Group has its next meeting coming up soon, but it’s pretty short notice so Patrick has asked me to spread the word (which I’m happy to do).

So, if you’re into Microsoft Virtualization and you’re in the London area on the evening of 16 April 2009, come along to Microsoft’s offices in Victoria to watch Matt McSpirit give a deep dive into Hyper-V R2 and SCVMM 2008 R2 before Adam Downie talks about Disaster Recovery and Business Continuity Management with Double-Take for Hyper-V.

Read more and register at the MVUG website.

Where does Citrix Essentials for Hyper-V fit in with SCVMM?

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Last month, as VMware prepared for their European conference, news of Citrix setting XenServer free and providing new management tools for Hyper-V was leaked. After the recent announcement of a beta for Microsoft System Center Virtual Machine Manager (SCVMM) 2008 R2, I decided to read up on the official announcement from Citrix to see how the Microsoft and Citrix management products fit in with one another.

First of all, to summarise the Citrix announcements last month, as well as announcing that the XenServer hypervisor will be free of charge, Citrix announced a 20-year collaboration project with Microsoft (Project Encore) as part of which they will release new management tools (Citrix Essentials – available for XenServer and for Hyper-V) and Microsoft will support XenServer in a future version of SCVMM.

The official coverage of the Citrix Essentials announcement also includes videos featuring Simon Crosby, CIO of the Virtualisation Management Division at Citrix and Mike Neil, the General Manager for Virtualisation at Microsoft. In one video, Crosby says that:

“You’ve known us as the guys who made the hypervisor free – that’s what Xen stood for and we’ve been partners with Microsoft with Hyper-V to make exactly the same true in the Windows world.

This is not about free hypervisors anymore – this is about free enterprise virtualised infrastructure, containing multiple servers, shared storage, live relocation – everything that you need to build, in production, enterprise class virtualised infrastructure is now free. It’s a game changer for the virtualisation industry because it completely changes the cost of adopting virtualisation.”

After saying how Citrix was setting everything free, Crosby contradicts himself by saying that it’s basically the hypervisor that’s free but that there’s a management suite (Citrix Essentials) that’s chargeable… (so the “essential” part is not free then!)

Even so, it’s a significantly lower price point than the last time I looked at VMware Virtual Infrastructure (which is the real point Citrix are trying to make), and Citrix Essentials will provide extra functionality, some of which would require the purchase of additional products from VMware:

  • Automated lab management – to streamline the process of building, testing, sharing and delivering throughout the application lifecycle, from development labs into the production environment.
  • Advanced storage integration – to expose advanced data and storage management features directly to a virtualized environment.
  • Dynamic provisioning services – for the on-demand deployment of workloads to any combination of virtual machines or physical servers from a single image.
  • Workflow orchestration – for the simplified scripting to automation of key management processes.
  • High availability – for the automatic restart and intelligent placement of virtual machines in case of failure of guest systems or physical servers.

But some of this functionality is also available in SCVMM, so how does Citrix Essentials for Hyper-V fit with the Microsoft Virtualization portfolio? That’s explained in another video, where Crosby highlights that:

“Citrix Essentials is a management pack of solutions that complement System Center VMM, adding value in areas relating to storage automation, lab automation and VM lifecycle automation that are entirely complimentary to the use cases that are part of System Center VMM today”

He continues to explain that, in terms of multivendor platform management, SCVMM is forging ahead and Citrix’s objective is to complement the Microsoft products by filling in the key areas of automation that are not part of the virtualisation management role (e.g. storage, lab and stage management), to complement Hyper-V and to co-exist with SCVMM.

Mike Neil explained that the Microsoft Virtualization platform is designed to be layered with the base hypervisor functionality provided in Windows Server and the System Center products layered on top to manage the virtual and physical machines, their operating systems and applications. This infrastructure is designed to be extended by partners and Citrix has taken advantage by producing Citrix Essentials for Hyper-V.

It helps that XenServer and Hyper-V are compatible at the hypervisor layer (indeed, Citrix developed the Linux integration components for Hyper-V). Citrix Essentials is intended to ensure that, whether there’s a Citrix or a Microsoft hypervisor in use, the same automation and capabilities are available for all workloads (and SCVMM can manage VMware ESX and ESXi hosts too, via Virtual Center).

Citrix Essentials for Hyper-V will go on sale in April 2009, priced at around $1500 per server.

System Center Virtual Machine Manager is available today from Microsoft, with attractive licensing arrangements (the Server Management Suite Enterprise) for customers deploying multiple System Center products.

Hyper-V is available as a role for 64-bit editions of Windows Server 2008 and as a standalone product offered free of charge (Hyper-V Server 2008).

Free Microsoft Virtualization eBook from Microsoft Press

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Every now and again, Microsoft Press makes free e-books available. I just missed out on the PDF version of the Windows Vista Resource Kit as part of the Microsoft Press 25th anniversary (the offer was only valid for a few days and it expired yesterday… that’s what happens when I don’t keep on top of my e-mail newsletters) but Mitch Tulloch’s book on Understanding Microsoft Virtualization Solutions is also available for free download (I don’t know how long for though… based on previous experience, that link won’t be valid for long).

This book covers Windows Server 2008 Hyper-V, System Center Virtual Machine Manager 2008, Microsoft Application Virtualization 4.5 (App-V), Microsoft Enterprise Desktop Virtualization (MED-V), and Microsoft Virtual Desktop Infrastructure. If you’re looking to learn about any of these technologies, it would be a good place to start.

Hyper-V Q&A

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Windows Server 2008 Hyper-VMicrosoft’s hypervisor-based virtualisation platform (Hyper-V) has been around for a few months now and, even though there is a whole host of information out there on the web, it’s still a source of confusion for many.

This post is a list of questions and answers for those trying to get started with the Microsoft hypervisor. It is based, in part, on information provided during the Hyper-V technology adoption programme and has been used with the kind permission of Microsoft Windows Virtualization product team, supplemented with additional information where appropriate.

Installation

Q. What are my options for installing Hyper-V?
A. Hyper-V is available as a role for x64 Editions of Windows Server 2008 Standard, Enterprise or Datacentre editions (i.e. not for 32-bit x86 or Itanium architectures, nor for web edition). The Hyper-V role is supported on either a server core or a full installation; however server core is recommended, due to its increased security. In addition, there is a standalone version of Hyper-V – Microsoft Hyper-V Server 2008 – designed for organisations who would like the benefits of Hyper-V but who do not run Windows (a comparison of features in the various Hyper-V products is available).

Q. I installed Hyper-V from the Windows Server 2008 media but it seems to be a pre-release version. Is that right?
A. Windows Server 2008 shipped with a beta version of Hyper-V. It is necessary to install an update to bring the Hyper-V components up to their RTM level, as well as to update the integration components in the virtual machines. John Howard has blogged extensively on obtaining Hyper-V, changes at RTM, upgrade considerations and more.

Q. How can I tell which version of Hyper-V I have installed?
A. Sander Berkouwer has provided some excellent advice for determining the installed version of Hyper-V on his blog (I also linked to some useful resources for those looking to upgrade a pre-release copy of Hyper-V).

Q. I’m not entirely comfortable with server core – how can I install the Hyper-V role?
A. John Howard has created step by step guidance on installing Hyper-V on Server Core. The basic steps are:

  1. After installation, logon to Windows and set a password.
  2. Configure the computername, firewall exceptions, remote desktop connection and then restart using the following commands (for more information on administering server core, see a few commands to get started with Server Core and there are also some alternative utilities available – including the HVconfig utility from Hyper-V Server):
    netdom renamecomputer %computername% /NewName:newcomputername
    netsh advfirewall firewall set rule group="Remote Administration" new enable=yes
    cscript \windows\system32\scregedit.wsf /ar 0
    cscript \windows\system32\scregedit.wsf /cs 0
    shutdown /t 0 /r
  3. Update Hyper-V to the RTM version (see Microsoft knowledge base article 950050)
  4. Enable the Hyper-V role using ocsetup Microsoft-Hyper-V
  5. Restart the computer using shutdown /t 0 /r

Q. Hyper-V relies on hardware assisted virtualisation. How can I tell if my hardware supports this?
A. Michael Pietroforte has written about the free tools that AMD and Intel provide to indicate whether a processor has the necessary virtualisation functionality and John Howard has also written about enabling hardware assisted virtualization in the BIOS. If your machine does not have the option (and some do not!), try a BIOS update.

Performance

Q. How does Hyper-V’s disk input/output (IO) compare with a non-virtualised solution?
A. In order to ensure that IO will never be reported complete until it has been written to the physical disk, Hyper-V does not employ any additional disk caching other than that provided by the guest operating system. In certain circumstances, a Hyper-V VM can appear to provide faster disk access than a physical computer because Hyper-V batches up multiple requests and coalesces interrupts for greater efficiency and performance. In Microsft’s internal testing they also found that:

  • Pass-through disks can sustain physical device throughput.
  • Fixed VHDs can also sustain physical device throughput at the cost of slightly higher CPU usage.
  • Dynamically expanding and differencing VHDs do not usually hit physical throughput numbers due to the overhead of expansion and greater likelihood of disk fragmentation.

Q. How can I measure performance in Hyper-V?
A. The MSDN website features a section on measuring performance on Hyper-V (specifically relating to running BizTalk Server in a VM but equally applicable to many other workloads).

Q. Sometimes, my virtual machines are paused automatically – why does this happen?
A. Rather than let a virtual machine run out of disk space, Hyper-V will pause the VM if the server is running critically low on space. In addition, an event (ID 16050) is written to the Hyper-V VMMS log.

Synthetic device driver model

Q. I’m confused about the various versions of the integration components (ICs) for virtual machines. Why does each release of Hyper-V have it’s own ICs?
A. Integration Components (ICs) are version specific – i.e. the versions used within the child partitions must match the version of Hyper-V that is running in the parent partition (Windows Server 2008 RTM was shipped with the Hyper-V Beta ICs). The Hyper-V RTM upgrade package (see Microsoft knowledge base article 950050) includes the updates for both the parent and child partitions. In addition, there are Hyper-V ICs for Linux and Professional, Enterprise and Ultimate versions of the Windows 7 and Windows Server 2008 R2 betas already come with Hyper-V integration components installed.

Q. Is there a method to incorporate the Hyper-V synthetic devices with Windows Preinstallation Environment (WinPE) for servicing?
A. Performing maintenance on a Hyper-V host from within WinPE represents a challenge for systems administrators in that, without the integration components, virtual hard disks (.VHDs) must be connected to the IDE controller (limiting the number of VHD’s that can be used at any given point in time) and legacy network adapters might be required in order to provide network access. Mike Sterling has a great blog post on using the Hyper-V integration components with WinPE (using the Windows Automated Installation Kit to create a custom WinPE image including the appropriate files extracted from the Hyper-V integration services setup disk). Attaching the resulting .ISO image to a VM and powering it on should provide full access to all synthetic devices.

Management

Q. What tools does Microsoft provide to manage Hyper-V?
A. Out of the box, Microsoft provides a Microsoft Management Console (MMC) snap-in (Hyper-V Manager). This snap-in is also available for x86 (32-bit) versions of Windows Server 2008, as well as for Windows Vista SP1 (x86 or x64 – see also Microsoft knowledge base article 952627). If you have the management tools installed on a Windows Vista machine then you might also find Tore Lervik’s Hyper-V Monitor Gadget for the Windows Sidebar useful.

Whilst Hyper-V Manager is adequate for managing a single host (locally or remotely), remote management with System Center Virtual Machine Manager (SCVMM) 2008 provides a centralised management console, designed to manage thousands of VMs across hundreds of physical servers running Virtual Server 2005, Hyper-V or even VMware ESX via VMware Virtual Center.

Hyper-V can also be managed using Windows Management Instrumentation (WMI), for example in a Windows PowerShell script and there is an open source PowerShell Management Library for Hyper-V available on CodePlex.

Q. My version of Windows Server 2008 does not seem to have the Hyper-V Management tools available.
A. Windows Server 2008 SKUs without Hyper-V or for other architectures (i.e. 32-bit x86 and Itanium) do not include the Hyper-V management tools.

Q. What else can SCVMM offer that the standard management tools do not?
A. Information on SCVMM may be found on the Microsoft website but the main features include:

  • Physical to virtual (P2V) and limited virtual to virtual (V2V) conversion (V2V is from VMware to Hyper-V – for Virtual Server to Hyper-V there is a free tool available (Matthijs ten Seldam’s VMC to Hyper-V Import Tool) and, for conversions from other products or back to physical hardware, various third party tools are available).
  • Orchestration of migration activities (i.e. quick migration for Hyper-V, VMotion for ESX).
  • Intelligent placement of virtual machines.
  • Management of virtual machine templates, virtual hard disks, CD/DVD (.ISO) images, etc.
  • Full integration with Windows PowerShell (with supported PowerShell cmdlets) as well as other System Center products such as System Center Operations Manager and PRO packs.
  • Virtual machine self-service for users to provision their own VMs, based on a quota system.

Q. I have a fully-patched Hyper-V host and SCVMM 2008 installation but SCVMM says my host needs attention. Have I missed something?
A. VirtualBoy Matt McSpirit blogged about a couple of updates required for Hyper-V and BITS when using SCVMM 2008. After installing these and rebooting, everything should be fine.

Q. How can I patch the virtual machines that are held offline (templates, etc.)?
A. Offline VMs may be patched using the Microsoft Offline Virtual Machine Servicing Tool.

Q. I’m trying to configure remote management for Hyper-V and it seems very difficult.
A. It can be! Luckily, John Howard had a few days vacation to use up and the result was a tool called hvremote. You can read more and download the tool on MSDN – but don’t use it if you’re using SCVMM to manage your Hyper-V hosts.

Q. I’m using the Hyper-V Virtual Machine Connection to access the console of one of my Hyper-V virtual machines but every time I press Ctrl+Alt+left to release the mouse (I do not have integration components installed) my screen turns 90°. Have i been infected with a virus?
A. Probably not! Some Intel chipsets use that key combination to rotate the display. Either turn off that functionality in the display driver settings or press Alt+Tab to break out of the VM and change the hotkey in the Hyper-V settings.

Environmental benefits

Q. Virtualisation is often cited as an enabler for green IT – how can that be? Surely I’m just moving the same heat and power requirements into one place?
A. An underutilised server still uses a significant proportion of its maximum power and consolidation of many low-utilisation servers onto a shared infrastructure will normally result in power supplies running more efficiently and a net reduction in power consumption.

By consolidating many servers onto onto a smaller number of servers using virtualisation then many servers may be retired. These older servers are likely to be less efficient than a modern server and will all require cooling, resulting in further power cooling savings.

Whilst disposal of old servers is not very “green”, some servers may be redeployed in scenarios where a physical infrastructure is still required.

Q. Does Hyper-V work in conjunction with the Processor Power Management (PPM) power savings in Windows Server 2008?
A. When the Hyper-V server role is enabled system sleep states (standby and hibernate) are disabled. The major savings in power and cooling requirements are gained by switching servers off and, by viewing overall demand for the entire virtualised infrastructure rather than working at an individual sever level, it is possible to use management technologies to bring servers on and offline in order to meet demand.

Virtual machine settings

Q. With Microsoft Virtual Server, it’s really difficult to access the virtual machine BIOS. Is there still a virtual machine BIOS?
A. Hyper-V VMs do still have a virtual machine BIOS; however, all of the BIOS features (e.g. numlock setting, boot device order, etc.) may be set in the virtual machine configuration or using a script. As a conseqence of this, Microsoft has removed the ability to access the BIOS at boot time.

Q. Hyper-V can import and export its own XML-based VM configurations but not the legacy .VMC format. Is there a way to migrate my Virtual Server and VirtualPC settings to Hyper-V without recreating the configuration manually (I’m not using SCVMM)?
A. As mentioned when discussing V2V migrations above, Matthijs ten Seldam (The author of VMRCplus) was written a VMC to Hyper-V import tool (remove the VM Additions before importing to save effort later).

Storage

Q. Can a virtual machine boot from SAN (FC or iSCSI), NAS, USB disk or Firewire disks (the boot order in the BIOS settings only shows floppy, CD, IDE and network)?
A. Virtual hard disks (VHDs) can be used to boot or run a VM from:

  • Local storage (IDE or SCSI).
  • USB storage (USB key or disk).
  • Firewire storage.
  • SAN Storage Area Network (iSCSI or fibre channel).
  • NAS Network Attached Storage (file share, NAS device).

It’s also possible to assign a non-removable volume (direct attached storage or a SAN LUN) to an IDE channel in the VM settings and to boot from that device.

Q. Is it possible for Hyper-V virtual machines to access USB devices?
A. Not directly and, although many people would like to see this functionality, Microsoft is adamant that this is a client-side virtualisation feature and have no plans to include USB support in the product at this time. There is a workaround, using the Remote Desktop Connection client though (and this approach can also be used for audio).

Q. How can I move VM images to another physical disk?
A. With Hyper-V, the simplest approach I’ve found for moving virtual machines is to export the VM and import it to a new location. Alternatively, you could move the VHD and create a new virtual machine configuration.

Networking

Q. I’m confused by the various network interfaces on my Hyper-V host – what’s going on?
A. It’s not as confusing as it first looks! The parent partition is also virtualised and all communications run via a virtual switch (vswitch). In effect the physical network adapters (pNICs) are unbound from all clients, services and protocols, except the Microsoft Virtual Network Switch Protocol. The virtual network adapters (vNICs) in the parent and child partitions connect to the vswitch. Further vswitches may be created for internal communications, or bound to additional pNICs; however only one vswitch can be bound to a particular pNIC at any one time. Virtual machines can have multiple vNICs connected to multiple vswitches. Ben Armstrong has a good explanation of Hyper-V networking (with pictures) on his blog and I described more in an earlier post on Hyper-V and networking.

Q. Can I use Hyper-V over a wireless connection?
A. Not directly, but there is a workaround, as described in my blog post on Hyper-V and networking.

Q. Is NIC teaming supported?
A. Not by Microsoft, but certain OEMs provide support, and Patrick Lownds has blogged about new Broadcom support for NIC teaming that seems to work with Hyper-V.

Legacy operating system support

Q. The virtual machine settings include a processor option which limits processor functionality to run an older operating system such as Windows NT on the virtual machine. What does this feature actually do?
A. This feature is designed to allow backwards compatibility for older operating systems such as Windows NT 4.0 (which performs a CPUID check and, if CPUID returns more than three leaves, it will fail). By selecting the processor functionality check box Hyper-V will limit CPUID to only return three leaves and therefore allow Windows NT 4.0 to successfully install. It is possible that other legacy operating systems could have a similar issue.

Q. Does this mean that Windows NT 4.0 is supported on Hyper-V?
A. Absolutely not. Windows NT 4.0 is outside its mainstream and extended support lifecycle and is not supported on Hyper-V and no integration components will be released for Windows NT 4.0.

Q. But one of the stated advantages for virtualisation is running legacy operating systems where hardware support is becoming problematic. Does this mean I can’t virtualise my remaining Windows NT computers?
A. The difference here is between “possible” and “supported”. Many legacy (and current) operating systems will run on Hyper-V (with emulated drivers) but are not supported. Windows NT is no longer supported, whether it is running on physical or virtual hardware. Microsoft do highlight that Windows NT 4.0 has been tested and qualified on Virtual Server 2005 and that Virtual Server may be managed (along with Hyper-V and VMware ESX) using System Center Virtual Machine Manager 2008.

Copying files between virtual machines

Q. I want to copy files between Hyper-V virtual machines. Is there a way to do this?
A. Microsoft make a distinction between client-side and server-side virtualisation usage scenarios and note that virtualisation servers are typically managed by a group of administrators who want to deploy a secure, locked down server by default (and do not want additional attack vectors created through virtualisation). This is the reason that Hyper-V does not include shared folder or drag and drop functionality (nor are there any plans to do so at a later date). The options for transferring data from one virtual machine to another are:

  • Setup a virtual network just as you would for physical systems.
  • Use a virtual CD/DVD creation tool and insert a virtual CD/DVD; this can be done while the virtual machine is running.

Microsoft’s stated position is that, in the case of client-side virtualisation, a single user is running a virtualisation product (e.g. Virtual PC) locally ands expects the capability to move files from one virtual machine to another. For this reason, Virtual PC includes shared folder support (but are not set by default).

Q. How does this work if I move a Virtual PC VM with shared folders to a Virtual Server or Hyper-V system?
A. In this case the shared folders guest components won’t load because the required server-side components are not available in Virtual Server or Hyper-V.

As XenServer goes free, new management tools are promised, and VMware gets another thorn in its side

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I may be a Microsoft MVP for Virtual Machine technology so my bias towards Hyper-V is pretty obvious (I’m also a VMware Certified Professional and I do try to remain fairly objective) but I did have to giggle when a colleague tipped me off this morning about some new developments at Citrix just as VMware are gearing up for next week’s VMworld Europe conference in Cannes.

Officially under embargo until next week (not an embargo that I’ve signed up to though), ZDNet is reporting that Citrix is to offer XenServer for free (XenServer is a commercial product based on the open source Xen project). From my standpoint, this is great news because Citrix and Microsoft already work very closely (Citrix developed the Linux integration for Hyper-V) and Citrix will be selling new management tools which will improve the management experience for both XenServer and Hyper-V but, in addition, Microsoft SCVMM will support XenServer (always expected, but never officially announced), meaning that SCVMM will further improve its position as a “manager of managers” and provide a single point of focus for managing all three of the major hypervisors.

VMware, of course, will respond and tell us that this is not simply a question of software cost (to some extent, they are correct, but many of the high-end features that they offer over the competition are just the icing on the top of the cake), that they have moved on from the hypervisor and how their cloud-centric Virtual Datacentre Operating System model will be the way forward. That may be so, but with server virtualisation now moving into mainstream computing environments and with Citrix and Microsoft already working closely together (along with Novell – and now Red Hat), this is almost certainly not good news for VMware’s market dominance.

Further reading

More licensing changes for virtualisation with Windows Server 2008

Posted on By Mark Wilson
This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Last summer, there was a big shake up of Microsoft’s licensing policies around virtualisation. Matt McSpirit provides the best explanation of licensing Windows Server in a virtual environment that I’ve seen on his blog but, today, I was notified about some new developments in the Microsoft Windows Server 2008 licensing model.

Quoting from the e-mail I received:

“Currently, if your physical server environment is running Windows Server 2003, matching version CALs are required for all users (i.e. Windows Server 2003 CALs). However, if you move your physical Windows Server 2003 Operating System Environments (OSE) to run as virtual machines hosted by Windows Server 2008 Hyper-V, Windows Server 2008 CALs are required. This is per the current use rights. With the change in our licensing policy, Windows Server 2008 CALs are no longer required if you are using Windows Server 2008 solely as a virtualization host. The only exception to this is if you are running Windows Server 2008 virtual machines, which would require Windows Server 2008 CALs.”

The e-mail then goes on to describe three scenarios by way of example:

“Scenario 1 – Customer deploying WS08 Workloads

  • There is no change in licensing or CAL requirements
  • This is irrespective of whether the customer deploys WS08 workloads (other than Hyper-V) in a physical or virtual environment.

Scenario 2 – Customer only deploys WS08 Hyper-V to consolidate WS03

  • WS08 CAL are no longer required
  • Customer will still need CALs for the appropriate WS edition (WS03 in this example)

Scenario 3 – Customer deploys WS08 Hyper-V to consolidate WS03 but also has WS08 deployments

  • WS08 CAL requirements will apply for the WS08 deployment
  • A CAL for a particular version of Windows Server allows the user/device to access all instances of that version of Windows Server (and prior versions) across the organization.”

So, if you have a Windows Server 2003 (or earlier) estate without SA and were thinking of virtualising on Windows Server 2008 (but didn’t want to stump up for the Windows Server 2008 CALs), this could save you a lot of money. Full details may be found in the updated licensing brief.