Ten things you always wanted to know about storage virtualization but were afraid to ask...

Ron Riffe

Ron Riffe, storage virtualization strategist, considers the most significant issues surrounding storage virtualization and the best way to implement this technology.

The buzz around the storage world today is virtualization - how customers, large and small, can maximize their storage infrastructures by taking advantage of virtual storage solutions through storage software and even partitions within the storage hardware itself.

Customers are still asking questions about what storage virtualization is all about, how they can implement these technologies and if their infrastructure is a good fit. Here are 10 questions customers might be asking themselves that could further help their understanding.

1.What does storage virtualization do for me?

Storage virtualization is a technique used throughout IT environments to simplify what tends to be a relatively complex underlying infrastructure. The idea is to separate the logical presentation of a resource from its physical implementation, presenting a simplified, seamless virtual view of the resource to applications and administrators.

2. Where should storage virtualization live?

The software that virtualizes storage can be run in a variety of locations. Generally the three most common locations are on a server, on a storage device or in the storage network. The storage network is receiving the most focus because it has the advantage of being able to support any connected server platform and any connected storage device. The next question that usually follows is...

3. Should I choose an in-band or out-of-band solution?

Some vendors want to make a big deal about the technical path they took to implement virtualization. The more important question is, 'As a customer, what results do you expect to achieve from virtualization?' The answer will guide you to an implementation.

Today only in-band implementations have the ability to deliver this full set of virtualization value. The smart thing to do is first decide what results you are looking for and then evaluate the solution based on how well they match your goals.

4. How can I avoid vendor lock-in?

The best way to avoid vendor lock-in is to virtualize the complete disk experience. If a vendor can get you to integrate your disaster recovery procedures to their proprietary replication services, or get you to load their proprietary multi-path device driver on all of your servers, or train all you administrators on the vendor's proprietary management interface, the vendor knows your switching costs will be high and that you are locked in.

If, however, you choose to virtualize your complete disk experience, you give yourself complete flexibility of choice in what underlying disk hardware you choose. And that flexibility will often result in lower overall costs.

5.What are my cost considerations?

When evaluating a virtualization solution, it's important to consider the direct cost of the solution in addition to the indirect savings that virtualization can bring. For example, most disk vendors charge extra money for their proprietary multi-path device drivers, replication services and management interfaces. (Remember, this is how they keep their margins up and keep you locked in.) Done right, virtualization can remove your need to buy all this proprietary software.

6. What sort of changes do I need to make in my environment to implement virtualization?

Storage virtualization is valuable, but if you have to make major modifications to your infrastructure to turn it on, the return on investment can be compromised. A good virtualization solution does not require any changes to your disk or storage network infrastructure.

Talk to your potential vendors about what changes are required to test and run their virtualization solution. Be aware that some solutions require you to buy new-generation SAN switches or new-generation storage controllers just to turn on virtualization.

7. How long has this virtualization product been on the market?

Customers are smart to consider not only vendor claims about their virtualization solution, but also how established the product is and how many upgrades have been made to the product. Some vendors are just now trying to rush to market with new offerings. In the world of software, version 1 is rarely as robust and reliable as version 6. Look for established products from reliable vendors.

8.Will virtualization enhance my management capabilities and ease the workload of my IT staff?

The idea behind storage virtualization is to improve the efficiency of your infrastructure, making storage management easier and more costeffective. Virtualization done right can take the complexity of multiple storage devices, storage vendors, device driver types, sets of copy services, management interfaces and give your administrators a common view of a single virtual resource.

And what's more, with transparent data movement between storage devices, many of the 2.00am jobs that storage administrators have to do can become 2.00pm jobs. Application outages can be avoided and work/life balance can be improved.

9. What are your performance, availability, capacity and scalability requirements?

In your evaluation of virtualization solutions, smart customers look not only for vendor claims but also external benchmarks. Some vendors have chosen to control everything in the virtualization path to ensure reliability and performance.

Others have taken a more federated approach by gluing together hardware components from one vendor with software components from another. Whichever approach you are evaluating, look for outside validation of vendor claims such as external benchmarks from organizations like the Storage Performance Council.

10.Will virtualization do for storage what Linux did for servers?

Before Linux, applications and system administrators were tied to an operating system and that meant being tied to the hardware that operating system supported. Done right, storage virtualization has the potential to do the same thing for your storage hardware. Do you want that freedom?

If so, ask the virtualization vendors you are evaluating if they see things the same way you do. Is virtualization of the complete disk experience (and giving you complete flexibility of choice) their goal too?

Armed with the above storage questions and answers, companies should feel well-equipped to tackle the challenge of evaluating storage virtualization. They just might find that they can save time, money and hassle when they make an informed decision about storage virtualization.