Technology buffs love talking virtualization: the big servers, tons of RAM, large SAN storage and networks pushing...
the boundaries of the latest standards. That's great, but in the real world, we need a handle on how to take advantage of the latest virtual technology without emptying the wallet. This is especially true in small and medium-sized businesses where virtualization cost savings can deliver some of the best benefits on a budget. Luckily, it's getting easier than ever to get a complete and reliable virtualization environment using Hyper-V technology for little to no cash.
Infrastructure: Use what you've got
The latest version of Hyper-V on Windows Server 2012 is great, but the stripped-down Hyper-V Server 2012 is even better because it's free (as is beer) and has lower minimum hardware requirements than standard Server. This release is not a crippled version of the hypervisor, either. Except for the GUI, it contains all of the features included with Windows Server 2012 proper. The slimmed-down minimum requirements mean you'll have to use Server Core, but you can use the Remote Server Administration Tools (RSAT) from your Windows 8 PC to manage the virtual host remotely. There are some management pieces you'll miss if you don't purchase the System Center Virtual Machine Manager, like private cloud fabric management, and some specific network management features, but it works out beautifully for those on a strict budget and smaller networks. If you plan to utilize clusters and shared storage, an investment in Virtual Machine Manager (VMM) is recommended.
RAM, RAM, RAM
You can get away with several cost-saving measures, but at the end of the day, virtual machines (VMs) need RAM. System memory is essential -- and usually cheap. Don't look at an old Small Business Server with 4 GB of RAM and think you'll be able to do much. You'll want to put as much RAM as you allocate to your machines, plus 2 GB for the host. If you'll need a domain controller with 2 GB, a database server with 8 GB and a file server with 4 GB, then you'll want 16 GB of memory.
Modern processors for a modern OS
The same need for memory goes for your processors. You will not do well to take a desktop system and run your servers on it. Your processors need virtualization hooks like Intel VT-x. Newer processors tend to have better virtualization performance due to advancements in how they interact with the hypervisor, so you'll want enough cores to handle your servers. Your typical modern servers will often ship with two CPU sockets. If your Intel Xeon CPUs with Hyper-threading contain four cores each, that gives you 16 cores you can address. The server should be fine for double that number of typical virtual machines and oftentimes even more than that if you have several mostly idle machines. You also have the option to give your server multiple CPUs, and with the Hyper-V maximum of 64 virtual processors per VM, you will not be left wanting for CPU power on your VMs.
Not everyone buys the biggest and baddest hard drives, and a smaller business can often get away with using slower, consumer-level SATA drives in their servers. When you consider where you will put your virtual disks, remember that each machine needs sufficient I/O. If you are using SATA hard drives, they are best for more sequential reads. Once you start placing VMs on that drive, you are sharing the disk. If you have a server that needs decent IOPS, like a database server, and you share that with a busy file server, then you are not only decreasing the available I/O, but you are mixing multiple types of disk access that are very different. Consider RAID 10 in either case for transactional performance reasons as well as data protection.
Many small businesses use network-attached storage (NAS) to provide shared storage for several applications. Hyper-V has supported iSCSI since Windows Server 2008, but you can also simplify shared storage setup by using standard file shares to store your virtual machines. This is a boon for any server administrator who doesn't have a SAN expert to fall back on. This newest support relies on an updated SMB 3.0 protocol, so you'll have to make sure your NAS will support that. In any case, if you are using a Windows file server to serve up storage, you could just upgrade to Windows Storage Server 2012 for your NAS and become instantly compatible.
You can also take advantage of local direct-attached storage and still get high-availability without clustering. Shared-nothing live migration allows you to migrate the entire VM from one host to another over the network. This is a great alternative to get high availability without the cost of additional storage. Just remember, this kind of migration isn't instantaneous. It will take a few minutes to push that entire VM to another machine, instead of seconds when using shared storage.
There are also several tools you can grab with a simple download. Veeam provides a free virtual machine backup utility VeeamZIP that works with Hyper-V. This no-cost solution allows you to keep proper snapshot-style image backups where you can drop them to cloud storage or your existing backup solution. Starwind's V2V Converter will allow you to convert physical machines to virtual without the need to buy VMM. Microsoft even has its own set of free tools in the Assessment and Planning Toolkit for Hyper-V to help you make migration decisions by analyzing your existing servers and doing workload discovery.
Easy to get started
There isn't much of an excuse to ignore virtualization, even in the smallest IT shops. With the added benefits of virtual machine portability, driver standardization and image-based recovery, running even one machine on a Hyper-V server can make perfect sense. Cost is not the factor it used to be, and with so many features in the free Hyper-V Server product, it isn't crippled by a bait-and-switch feature set. It really is ready for production.