Virtualising SBS in the SME: choosing a hypervisor and planning a virtual infrastructure
Virtualisation is a powerful tool. You can use it to consolidate multiple applications on a single piece of hardware, or use several different operating systems at the same time. Often seen solely as the province of the enterprise data centre or the development lab, virtualisation is rapidly becoming a powerful tool for the SME as well, providing new routes to disaster recovery, and helping future-proof legacy applications.
Install Virtual Server 2005 R2 with our 16 Step Tutorial
Virtualising Microsoft SBS
The most obvious reason to virtualise Small Business Server is for disaster recovery. Backing up SBS has never been easy — and restoring on to new hardware is often fraught with difficulty. It can take days to get a functioning install back and running; days when your clients are waiting for key data and business services. With a virtual server things are a lot simpler, as virtual disk images can be backed up using management tools — while they’re still running. Snapshot images like this can be stored on external hard drives, or even uploaded to off-site storage services. Recovery is as easy as installing a new hypervisor on a new machine, and then loading the latest server image. Your client can be back online in minutes; quicker if they’ve got a standby machine ready to go.
Then there’s dealing with mergers and takeovers. If your client buys another company and wants to consolidate IT services, without losing any functionality, you may well want to take an existing SBS 2003 install and virtualise it so it shares hardware with another SBS running a separate domain. Sharing hardware means it’s easier to migrate data and applications, while keeping services functioning during the transition. The same approach can be used to keep an SBS system up and running while you move a client’s infrastructure to a different OS release, or to newer, faster hardware.
SBS can also be used as a host for other operating systems — so if your clients have an ageing mission-critical Windows NT or Windows 2000 application, you can run it in a virtual machine on more modern hardware. As today’s hardware offers more and more cores, along with 64-bit support, there’s plenty of power on even a cheap commodity server — and that means it’s a lot easier (and a lot cheaper!) to consolidate servers onto one server than to run an entire machine room full of hardware. You do need to consider hardware reliability and indeed security when you do this, as a single failure or theft will now shut down the equivalent of several servers.
There’s another good reason for looking at the combination of virtualisation and SBS. Microsoft’s latest version, SBS 2008, is built on Windows Server 2008 and comes with the same virtualisation rights as Windows Server 2008 Standard. Moving to a virtualised SBS install now will make migration to SBS 2008 a lot easier — especially if your clients are currently using a 32-bit SBS install, as they’ll need to switch to 64-bit servers for SBS 2008.
Virtualisation also makes sense if you’re just trialling new software. Microsoft offers a library of virtual machine images (using its VHD virtual hard disk format) to help you try out new software or demonstrate it to customers. Available images include Exchange Server 2007, the upcoming ‘Stirling’ release of the Forefront security tools, and the System Center Essentials management suite, as well as test images of Vista and Windows Server 2008.
Once you’ve and your clients have decided to virtualise their systems, it’s time to decide just what tools to use, and how you’ll provide management services.
Choosing a hypervisor
With Microsoft now offering three hypervisors, the choice can seem difficult. In fact they each occupy very distinct niches, even if at first glance they appear very similar. You’ll need to use your clients’ requirements to finalise which you use — but as they’re either bundled as part of the operating system, or available as free downloads, there’s very little financial risk involved with whichever hypervisor you choose.
1. Microsoft’s original hypervisor is still available, and still well worth considering. The latest release, Virtual Server 2005 R2 SP1, is available as a free download from Microsoft.com. It’s quite a small download; just over 40MB for both the 32- and 64-bit versions. Microsoft’s Senior Product Manager for Integrated Virtualization, Edwin Yuen, describes it as “Really for people who aren’t using Hyper-V yet”. There are still a lot of servers that can’t use Hyper-V, as they don’t support the latest CPU virtualisation technologies. You may not get the same performance as Hyper-V, but you’ll still be able to use Virtual Server. If you’re planning on virtualising non-Windows operating systems, then Virtual Server has an edge over its newer siblings, as it can support a more diverse set of guest operating systems.
Virtual Server’s Linux support means you can build a hybrid server that uses a mix of Linux and Windows applications — so you can be feeding information from a SQL Server database to a SugarCRM system. Virtual network adapters mean you can route information between host and guest operating systems without leaking information to the outside world — something that’s increasingly important as a means of offering Data Loss Prevention to at-risk clients in regulated industries.
The latest version of Virtual Server will be the last, as Microsoft has now released its new generation of hypervisors. Originally code-named ‘Viridian’, it finally launched (after a long and troubled beta programme) during the summer of 2008 as Hyper-V. It may not have all the features that were originally promised, but it’s still a powerful tool with much to offer your clients.
2. Hyper-V is a very different tool to Virtual Server. It works with the latest generation of CPUs from Intel and AMD, taking full advantage of their built-in virtualisation support. This means there’s less of an overhead and guest operating systems will run faster, with better access to the underlying hardware.
If you’re intending to use Windows Server 2008 as a host operating system (or Small Business Server 2008 which is based on Windows Server 2008), then you’ll probably want to use the Hyper-V role in Windows Server 2008. Make sure that you’ve downloaded the latest updates from Microsoft before you do this, as Windows Server 2008 comes bundled with a pre-release edition which Windows Update will update to the final version. SP2, due 2009, will include the final version of Hyper-V, and allow you to slipstream that into installation images.
Hyper-V installs as a server role, and can be managed using the standard Windows Server 2008 management tools. If you’re only using one or two guest operating systems on a single host you won’t need additional management tools. Standard remote access tools will let you work with the guest operating systems, and the Hyper-V management plug-ins can be used through a remote desktop connection to the host server.
3. Another alternative is the standalone Hyper-V Server. This is version of Hyper-V that doesn’t need a host OS. Command line tools let you create and load virtual machines, while you still have access to the same remote management interfaces — so you can use SCVMM to control and manage your virtual machines. The built-in CLI is actually a highly modified version of Windows Server 2008 Core, optimised for a single role and unable to support additional services. Microsoft suggests using it for non-Windows workloads, as there are no bundled guest Windows OS licences with Hyper-V Server, unlike the bundled Hyper-V that comes with Windows Server 2008.
You can run a wide range of operating systems on Hyper-V, with support for Windows Server 2000, 2003 and 2008 (including 32- and 64-bit versions of Server 2003 and 2008), as well as SUSE Linux Enterprise Server, though this can only run with one virtual processor. There’s likely to be support for other operating systems in the future — and it’s even more likely that you’ll be able to run your choice of guest x86 OS’s with few problems (though there’ll be no support from Microsoft).
The minimum requirements for Hyper-V
are fairly mainstream:
• An x64-based processor running an x64 version of Windows Server 2008 Standard, Windows Server 2008 Enterprise or Windows Server 2008 Data Center.
• Support for hardware-assisted virtualisation, either Intel VT or AMD Virtualisation.
• For security reasons you must also use an NX bit-compatible CPU, with hardware Data Execution Prevention (DEP) enabled.
• You’ll also need at least 2GB of memory.
If performance is a key metric for your clients, then you’ll want to use Hyper-V. You don’t need to run it on a full install of Windows Server 2008, as it’ll happily run on the command line Server Core. This approach works well for managing Web farms, as a single image can be replicated and installed multiple times. You’ll find the SCVMM tools useful here, as they can give each image a separate identity, configuring server IDs as they’re deployed (see chart above).
It’s actually very easy to migrate from one of Microsoft’s hypervisors to another. They all use the same VHD virtual disk format, so a virtual machine created on Virtual Server can be run on a machine running Hyper-V. If your client wants to upgrade their hardware and server OS, you can just take the VHD files from the old server, install them on the new system, and straight away be running the same virtual machines — and the same applications — without having to do any configuration or installations. Down time will be kept to a minimum, and your client’s users will be able to carry on using the applications the way they always have.
You can simplify the migration process still further by using the migration tools built into System Center Virtual Machine Manager.
Both Hyper-V and Virtual Server have their own management tools. Virtual Server uses a Web-based administration server that lets you control and manage all the aspects of your servers (and even use them) through your browser. If you’re running Hyper-V on Windows Server 2008 you’ll get access to a new set of management console plug-ins, which can be used locally or over a network. While the standalone Hyper-V Server has its own command-line management tools, these only give you access to a subset of its management capabilities, and really only get you started. A standalone management tool for Vista will help you get started, but if you’re managing several Hyper-V Server installs you’ll need to take advantage of Microsoft’s System Center Virtual Machine Manager.
System Center Virtual Machine Manager
Microsoft’s System Center Virtual Machine Manager 2008 (SCVMM) is a cross-platform management tool for virtual machines and hypervisors. It integrates with the rest of the System Center toolset, and lets you prepare and deploy virtual servers. You can use it to manage Virtual Server, Windows Server 2008’s Hyper-V installs and Hyper-V Server. It also supports VMware’s VI3 infrastructure, giving you one place to control all of a client’s virtual machines.
SCVMM is a powerful tool which mixes client and server tools. The client software runs on Windows XP and Vista, while the server component needs to run on Windows Server 2008, with a back-end SQL Server database to store information about managed systems (you can use the free SQL Server Express for this). You’ll need to manually connect to the systems you want it to manage but it will enable the Hyper-V role on them automatically if it’s needed — expect to reboot if that’s the case. If you’re targeting Windows Server 2003, then SCVMM will also install Virtual Server 2003. There’s no need to have IIS running on a SCVMM-managed Virtual Server host, as it handles all the management duties.
You can use SCVMM to convert existing physical machines to virtual servers. All you need to do is connect to the server you want to convert from SCVMM. It will then use Volume Shadow Services to create an appropriate VHD, which can be moved to a host server and started. There’s no need to reboot the server you’re converting — as it can be converted while running. Older servers without VSS-support can still be converted, though these will use WinPE to build appropriate installation images.
If you’re using Microsoft System Center Operations Manager, you’ll be able to use it with SCVMM to manage all your physical and virtual servers in one place, with Operations Manager agents inside the VMs. This approach lets you use Operations Manager management packs with virtual machines, tying VM performance and resource usage to SCVMM automated operations — adding servers to farms as needed, or moving VMs to different physical servers depending on workloads.
SCVMM uses PowerShell to manage VMs running on Hyper-V servers. Any time you create an action in SCVMM you’re actually creating a PowerShell script, which is then run by the server. Once you’ve created scripts you can edit them and reuse them, as well as triggering actions from machines that don’t run the SCVMM client.
Planning your virtual infrastructure
Setting up and running a virtual infrastructure for a client can be a complex task — especially when you need to consolidate existing servers onto new host systems. The question of just how many hosts you need is a complex one, and while you can use various rules of thumb to estimate your client’s needs, Microsoft has useful planning tools.
One option is MAP, the Microsoft Assessment and Planning toolkit. You’ll find this at www.microsoft.com/MAP. What Microsoft calls a Solution Accelerator, MAP is a tool to help you define desktop and server infrastructures. While the most common use is to plan Vista upgrades, it’s also able to assess your client’s servers to determine what can be virtualised and how. You’ll need to run it for some time to collect server performance statistics. The resulting report gives you a recommended server consolidation plan, which you can then use to handle P2V conversions.
SCVMM also includes tools to help manage where VMs run. You can use the Intelligent Placement tools to determine where best to place your guest OS’s. Every time SCVMM moves VMs between hosts it analyses the available hosts to determine where the best host for the VM will be, in order to ensure the best possible performance.
Effective planning and good management
are key to achieving a successful virtual infrastructure — much like any physical network. If you make sure that you’ve dotted the i’s and crossed the t’s before you start the move, you’re much less likely to have any problems, and much more likely to have satisfied clients.
Microsoft tunes up licensing policies
One of the real frustrations of dealing with software is licensing policies. End User License Agreements are often hard to read and impossible understand and virtualisation increases the confusion. Recently Microsoft overhauled its licensing agreements to make them fairer: a move that will benefit SMEs as well as larger enterprises.
The new licences reflect the reality of virtualisation, to encourage people to deploy on Hyper-V Server. For anyone looking to consolidate servers or build high availability and disaster recovery into their systems, this is an extremely positive move.
The essence of the server licence changes mean that you can now migrate VMs across a range of hardware as and when you need. This means that as you consolidate customer servers onto VMs, you do not have to purchase unnecessary or unwanted licences. It also means that if you want to migrate customer servers onto a hosted platform, you can do so using VMs with their licences — as long as the customer retains ownership of the VMs (note this in your terms and conditions).
Client licences change too. Windows desktops built inside VMs can now be provided to home workers and contractors. These machines are deployed using the Microsoft Virtual Enterprise Centralised Desktop license. Under this program, the company creates secure VMs designed to run corporate applications and to connect to company servers. When deployed they attract a small licence fee of $110 per PC per year. If the desktop is deployed to a staff member who wants to occasionally work from home, the cost drops to just $23 per PC per year.
Install Virtual Server 2005 R2 with our 16 Step Tutorial
The Microsoft virtualisation team blog looks at backing up Hyper-V virtual machines:
Microsoft’s instructions for installing Virtual Server R2 on SBS 2003:
Learn about how you can use virtualisation with SBS 2008 and Hyper-V (both Server and Windows Server 2008 editions):