How to install virtual servers with Hyper-V
In part two of our virtualisation series, we look at choosing the right infrastructure and installing virtual servers with Hyper-V
In the first part of this series - Implementing virtualisation through Hyper-V - we covered the benefits of virtualisation and listed some of the powerful features that are new or improved in Windows Server 2012.
In this part we’ll discuss how to implement virtualisation, from choosing the right infrastructure through to installing virtual servers with Hyper-V.
It’s worth spending time planning how virtualisation will be implemented: the larger the infrastructure the more important this becomes. Writing a list of which services to be virtualised, along with the processor, memory, disk and networking requirements for each, will help define the hardware required to run it all. In addition to servers, there may be a need for other types of virtual machines (VM) such as desktops, creating a virtual desktop infrastructure (VDI).
As virtual servers will happily co-exist with physical ones, it’s possible to migrate services over a period of time and this can help keep the initial costs down. Make sure any components selected have upgrade potential to allow the infrastructure to grow over time.
Ideally, companies should only run a small set of services or applications in each VM, although as we’ll see in the next part of this series, licensing costs may limit the number of VMs. Where possible, avoid any single points of failure by using resilient components such as fault-tolerant disk arrays, multiple network paths and additional power supplies. The possibility of downtime can be reduced further by clustering the servers, and enhancements in Windows Server 2012 make this a lot easier than previous versions.
As virtual servers will happily co-exist with physical ones, it’s possible to migrate services over a period of time and this can help keep the initial costs down
Although the size and scale of virtualisation products vary enormously, essentially they all need three main hardware components – storage, servers and networking. As storage is key to the rest of the virtualisation design it's worth looking at first. For small businesses this can be as simple as a set of hard disks inside a server, but as the size of the organisation increases then a shared storage solution is likely to be the better option.
Shared Direct Attached Storage (DAS) allows more than one server to connect to an array of drives, so running VMs can be quickly moved between servers. For the greatest flexibility a Storage Area Network (SAN) is the ideal choice, but unfortunately they are expensive and can be complex to manage. VMs can also be run from Windows Server 2012 file server shares and these can be implemented in a variety of scenarios, providing even more flexibility. For the best performance and reliability keep the storage network separate from other network traffic.
The servers themselves will need to have enough processor power and memory to support the VMs they'll be running. They’ll need to support virtualisation, although most modern servers do. If a SAN is being used to store the VMs then each server will only need minimal storage to support booting the operating system. If there’s an iSCSI SAN and the servers support iSCSI booting, there’s no need for hard disks in the servers at all as they can be configured to boot from virtual hard disk files on the SAN.
Each server will need a minimum of two network connections. Hyper-V virtual networking components integrate closely with their assigned network connections, so it’s best to exclude one of these from Hyper-V. This will mean there will still be a connection into the server even if there are problems with Hyper-V networking. If a VM will have a large volume of traffic, it’s normally best to dedicate a fast network connection to it.
Obviously, costs will vary greatly depending on the amount of redundancy built into the equipment and the specification required. As a very rough guide, servers suitable for virtualisation can start at around £5,000; DAS boxes can easily cost £10,000 and above depending on how much storage is needed. Significant costs can be incurred if a SAN is added to the infrastructure: these costs will comprise the SAN itself, dedicated network components and the skills needed to implement it all (unless they’re present in-house). There’s also a requirement to have a comprehensive backup strategy.
Installing the Hyper-V role
If Server Manager is not already running, click on the icon at the bottom-left of the desktop or use search to find it. Click on "Dashboard" on the left-hand side of Server Manager and then "Add roles and features" in the middle. Run through the wizard, selecting "Role-based or feature-based installation", then make sure the server is selected on the next screen. On the Roles screen select Hyper-V, and if the "Add features that are required for Hyper-V" screen appears, make sure the management tools option is selected and click on "Add Features".
Click through the screens until you get to "Create Virtual Switches". As discussed earlier, leave at least one network card unticked so it can be used to manage the Hyper-V server, and select at least one other card to be used for the virtual network; the box on the Migrations screen can be left unticked as this can be configured later. On the "Default Stores" screen, change the locations as appropriate for the company’s disk configuration and then click on Install on the final screen. Reboot the server and log back on.