Overall, virtualization is a good thing, said Dave Asprey, VP of Cloud Security at Trend Micro, in a presentation at the recent Interop IT conference in Las Vegas.
But the problem is that, like driving — or dating — in high school, Asprey said, everyone’s doing virtualization now, but most aren’t doing it very well.
One key to using virtualization properly is knowing when it makes sense to virtualize servers. Here are seven situations in which Asprey said virtualization won’t benefit organizations:
1. When you already have predictability and stability
When deciding what to virtualize, Asprey recommends following the old rule, “If it ain’t broke, don’t fix it.” If something is already working well, adding virtualization to the mix will only add complexity and increase the possibility of downtime.
The exception, of course, is when you have to use an old operating system that’s no longer supported — in those cases, you’ll have to virtualize whether you want to or not.
2. When servers are already running at high capacity
Likewise, if a server is already running at high capacity, virtualizing won’t provide much benefit.
One of the biggest benefits of virtualization is that it allows companies to consolidate servers and get more out of the hardware they already have. But if a physical machine is already running at close to its full capacity, virtualizing will just add another component that draws CPU power and other resources.
3. When software licensing is tricky
As virtualization becomes more common, things are improving, but many software vendors still don’t have a virtualization model, Asprey says. That’s especially the case with highly specialized software from small vendors.
Your best bet in those situations: Hold off on virtualizing for now, and talk to the vendor and try to use your clout to negotiate a virtualization-friendly license.
4. When virtual machines just won’t work well
Some machines simply run better without virtualization, Asprey says. Those include machines with:
- High I/O apps like databases
- Disk-intensive workloads
- Graphics-intensive apps, and
- Hardware cards without virtualization drivers.
5. When applications are highly time-sensitive
Virtual machines use their own clocks, which are different from the clocks used by the host machine. Over time, tiny differences can lead the two clocks to drift apart, Asprey warns.
For that reason, companies may want to avoid using virtualization for highly time-sensitive applications, such as financial trading systems or some industrial control systems.
6. When you have no safe way to manage encryption keys
With physical servers, IT departments can keep USB drives with encryption keys locked and then plug them directly into servers when they’re needed. But with virtual servers that doesn’t always work, because virtual machines move and it can be tough to find which USB ports correspond to which machine.
Therefore, virtualization may not make sense for machines with high security needs, unless the company has a way to manage those keys. Asprey recommends policy-based encryption key management.
7. When you can’t pay for it
When used in the right situations, virtualization should help companies save money — but only if IT has the initial budget to implement it properly and make sure everything works, Asprey says. Even with low-cost or free open source tools, companies still need to pay for expertise and staff time to virtualize.
Doing a bad job will only require the company to spend a lot of money to fix problems down the road. Best bet: Don’t start virtualizing until you can convince the CFO to fully fund the project.