The Ins and Outs of Server Virtualization
In the majority of today’s server rooms, it is evident that virtual server implementations are becoming the norm. Companies have quickly come to realize the cost-savings and other advantages virtual servers provide over physical servers.
The ability to run several logical servers on each physical machine allows a company to save on real estate in the server room, realize energy-savings on reduced heat output and cooling requirements, and greatly reduce their infrastructure investments. Furthermore, virtual servers also afford flexibility and redundancy, allowing easy balancing of server loads as well as additional business continuity.
Is Server Virtualization Right for Your Company?
As an IT manager or employee, a good time to consider whether to make the move to a virtualized environment is when it’s time to replace existing servers or add new servers to your infrastructure. Before you obtain quotes for new equipment, consider the benefits you can reap by migrating to a virtualized infrastructure:
- Maximized hardware usage
- Lowered capital investment
- Reduced maintenance costs
- Smaller energy and utility bills; and more
It is important to note that you will also still need a couple physical machines for business continuity, in the event of an outage or an issue with your virtual configuration.
Analyze Your Virtualization Requirements
To figure out whether virtualization is a good fit for your company, you’ll want to take some time to calculate the energy outputs and cooling requirements per server, to generate the hardware necessary for an appropriate virtual to physical ratio. If needed, utilize tools from providers like VMWare and Microsoft to assist with this process. Also, you may want to consider bringing in an experienced server virtualization consultant to help with the planning and implementation of your virtual environment.
Reevaluate Your Infrastructure
Migrating to a virtual framework is a perfect time to review and reevaluate what are truly necessary components of your IT infrastructure. Have your data storage needs evolved? Do you still need to be running the old accounting database server? Are there tools that can replace the functionality of existing server functions roles that don’t require a separate virtual machine?
Now is the time to update your existing hardware - or to order new equipment - with extra processors, memory, and hard drive space to accommodate the requirements of hypervisors - the hardware or software that will run your virtual machines.
Prior to migration you’ll also want to arrange for the proper training of IT staff, to equip them with the knowledge to skillfully support this change in infrastructure, before it goes live. Utilize demos, webinars, and as much hands-on training as possible so your employees feel comfortable and confident in maintaining a virtual environment.
Time to Migrate
Before you jump into your migration, you’ll need to decide which virtualization software platform is right for your business. The market leader, VMware VSphere, is a popular choice. VMWare is a solid, long-term market leader, but is not always the most economical choice. Microsoft’s Hyper-V and Citrix’s XenServer are also available choices that may make sense to select, depending on your core environment. Microsoft is a winner on cost, while VMWare and XenServer both have deeper offerings and myriad core features.
When you’re done rolling out your test environment with your virtual software of choice, and feel comfortable with its setup, then it’s time for production! But where should you begin? It’s probably best to start with machines that are not mission critical to your production environment – just in case you run into roadblocks. Perhaps an FTP server, backup domain controller (BDC), or another mirrored server would be a good place to start.
Once things are running smoothly, you can move onto your more critical email and database servers. As a rule of thumb, be sure to leave at least one physical domain controller in the network, in the event of an outage, to help expedite recovery processes. Another good rule to follow with a virtualized environment is to ensure that your virtualization management tools are run on a physical laptop or PC. This setup will give your admins better access in the event of an issue with the virtual infrastructure.
Don’t Forget the Applications
While most basic applications should run without any hiccups in a virtual environment, there may be issues with migrating large databases, in terms of functionality, licensing, and support. For instance, if you decide to use different naming conventions for your virtualized servers, there may be coding changes required – such as in an Accounting or ERP system – especially when those servers communicate and send data back and forth between multiple applications. To prevent any issues from arising, be sure to check with your application vendors prior to beginning your server migrations.
Selecting Your Virtual Hardware
While virtualizing your physical environment should result in overall cost savings in terms of hardware, you still may need to invest in server hardware that will be robust enough to handle the number of virtual machines (VMs) that you intend to run on it. So what are some of the key factors you will need to examine when selecting the appropriate hardware? Consider the following list:
Memory (RAM) – Virtual servers require a lot of RAM. When you think about it, that requirement is fairly obvious, given that physical memory must be assigned to each VM. So installing as close to the maximum amount of RAM as possible would be ideal.
Storage – Concerning storage, you’ll want to calculate the current amount of hard drive space in use and increase that amount for future planning, including the possibility of adding new virtual machines. In general, it’s best to map LUNs (logical unit numbers) to virtual servers, or use iSCSI or NFS to link to central storage arrays. This setup can speed up storage migrations, make them more flexible, and reduce backup times.
CPUs – While virtual machines are generally not huge processor hogs, there are still basic requirements that should be met to prevent overloading. A safe number would be around 4 vCPUs per CPU core.
Network Interfaces (NICs) – Ideally, a virtualization host server should have 4-6 NICs, in order to facilitate high availability and business continuity.
Tips for Migration
- Instead of performing a physical-to-virtual (P-to-V) migration for each physical machine, it is best to rebuild your servers in the virtual environment and then migrate the applications, configurations, and data. Doing so allows you to start with a fresh environment and prevents issues that could arise with the conversions.
- Build new domain controllers, as well as Linux servers, in the virtual infrastructure.
- If executing a P-to-V migration makes the most sense for your setup, locate a reputable tool that has the highest rate for successful conversions.
Monitoring and Managing Your Virtual Environment
Regardless of the virtualization software you choose, there should be management tools included in your licensing bundle. It is recommended to set up alerts and notifications for any critical events that might occur. And you’ll want to regularly check on server functionality and resource allocations to ensure nothing is being maxed out.
Don’t Forget the Backups
Backing up virtual machines (VMs) works a little differently than traditional backups. You can choose to install an agent on each VM and backup that way – depending on your comfort level - or you can purchase virtualization software that can be configured to take a snapshot of the server and then backup the snapshot. The latter method reduces the performance impact to the network, as well as each server.
For most of today’s network environments - with the proper setups - virtualization wins out for its agility, flexibility, ease of management, quick provisioning, improved performance, cost-savings, and more. Isn’t it time to see what virtualization can do for your network infrastructure today? West has a team of professionals that can provide expert services for any stage in the IT lifecycle, from assessment, strategy and design, through pilot, implementation, operational training, and optimization. Learn more about our server virtualization and storage services.