Virtual Machine Backup: What You Should Know?

Every company understands how important it is to back up mission-critical data or even archive emails for future reference. Backups are not only crucial for disaster recovery purposes, but also for the long-term busi­ness continuity requirements of your company. With the recent growth in virtualization as a way to maximize resources and implement consolidation measures, companies will need to change the way they think about backups. Now, more than ever, it is necessary to consider your virtual­ized assets when deciding what to back up and how.

"The big thing that's changed rela­tively recently is the criticality of what we're virtualizing," says Dave Russell, research vice president at Gartner (www.gartner.com). "It's really the impor­tance of the payload of the data. A few years ago, it might well have been test and development data that was being virtualized, but now it's the production, mission critical workload; the things that we normally would've protected in the past on physical machines."

Virtual machine

For that reason, it's important to come up with a VM (virtual machine) backup policy that is equal to your policy for traditional data backups. You need to prioritize virtualized data and applications just as you would data stored in a more physical envi­ronment or else you may not be able to fully restore your critical systems in the event of a temporary outage or widespread failure. We'll discuss a few of the best practices you can follow when backing up your VMs.

Understand your environment & backup needs

The important thing to remember about virtual machine backup is that it isn't exactly the same as traditional backup environments and that "doing business as usual from a backup perspective won't typically work effec­tively in a virtualized environment," says Russell. He explains that one of the biggest problems facing companies today is the sheer amount of solutions on the market that are specifically built for smaller implementations. For in­stance, you may start with a small pilot project and your "virtualization admin­istrator can download a tool and feel very confident it's going to work," he says, but once you start to deploy 300 or 500 virtual machines at the same time and reach critical mass, "the cracks will start to show."

Veeam Backup & Replication

Russell also points out that tradi­tional backup is a resource-intensive process that can fill up your input and output streams as can other resources such as CPU and memory. Because virtualization is all about maximizing ef­ficiency and putting numerous virtual machines on one physical server, it can lead to overloading your equipment. If you were to implement 20 VMs on one physical machine, stack or in­crease the density of the VM images, and then try to back it up with 10% of your resources, you would be "over­subscribed by 200%," says Russell. You need to make sure you have systems in place that can handle that amount of traffic and prevent overtaxing your infrastructure.

Another key to successful VM backup is to consider what you'll need to protect in the future. Rather than focusing on the here and now, you'll need to project where you see your company a year or more from now. One solution may work perfectly fine with five virtual machines, but as you grow to 50, 500, or 1,000 machines, Russell says, you have to determine who's going to be responsible for them. From there, you have to decide what types of plug-ins, applications, and reporting tools, you'll need. That's where doing your due diligence upfront will really pay off.

Choose the right solution

When choosing a virtual machine backup solution, most any program will do in the short run, however it is important to choose a solution that will meet your company's needs over a long period of time. Russell compares the process of choosing a VM backup solution to buying a car. "Any car can seem great one day," he says, "but what do you really need from it over a long period of time?"

Some backup solutions are wizard ­like and walk you through the selec­tion process. Others, Russell says, "will require encoding from the ground up." Your company's backup needs and staff expertise will likely dictate whether you'll need a fully formed so­lution or something more customizable.

Some backup solutions are wizard ­like and walk you through the selec­tion process

You'll also want to consider di­saster recovery and other factors when shopping for backup solutions. You may be able to store VM images on a server, but will you be able to access them immediately if your com­pany experiences an outage? Russell recommends finding a solution that lets you make the target location (where you're writing the virtual ma­chine) a cold standby server for your company to use in case of an outage. That means that if there's a failure of any kind in your primary system, you essentially have an up to date replacement waiting in the wings.

As with any technology invest­ment, cost will always be a factor. It's important to speak to vendors to figure out how they charge for their services and whether they are com­patible with your internal systems. Russell says that some vendors offer a free backup capability in their hypervisors, but just because they're free "doesn't mean that they will meet your requirements." Some vendors also charge by the socket or by the terabyte, so Russell says "you'll need to feel what type of model is going to work for you at scale when you de­ploy it throughout the environment." The more accurate you are with your projected number of virtual machines, the better chance you have of not overpaying for a solution.

Make a backup schedule & stick to it

Once you have a backup solution in place, you can't simply set it and forget it. You need a game plan that de­tails the systems you need to back up and how often. "The frequency really depends on several things but most fundamentally the criticality of the data and the change rate of the data," says Russell. "With some systems, the new and modified data is pretty infrequent, so you could argue that you only need to protect them once a week. Other systems are either so important or are being added to and extended on such a regular basis that maybe snapshotting them once an hour may be appro­priate." You can save money as well as crucial resources by backing up only what is necessary and following a strict policy.