Virtual storage queries answered

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

But customers are still asking questions about what storage virtualisation is all about, how they can implement these technologies, and if their infrastructure is a good fit.

Francois Vazille, business unit executive for system storage at IBM fi elds 10
questions customers might be asking themselves that could further help their
understanding.

What does storage virtualisation do for me?

Storage virtualisation 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.

Where should storage virtualisation live?

The software that virtualises 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...

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 virtualisation. The more important question is “as a customer, what results do you expect to achieve from virtualisation?”

The answer will guide you to an implementation. Today, only in-band implementations have the ability to deliver this full set of virtualisation 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.

How can I avoid vendor lock-in?

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

If, however, you choose to virtualise 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.

What are my cost considerations?

When evaluating a virtualisation solution, it’s important to consider the direct cost of the solution in addition to the indirect savings that virtualisation 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, virtualisation can remove your need to buy all this proprietary software.

What sort of changes do I need to make in my environment to implement virtualisation?

Storage virtualisation 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 virtualisation 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 virtualisation solution. Be aware that some solutions require you to buy new-generation SAN switches or new-generation storage controllers just to turn on virtualisation.

How long has this virtualisation product been on the market?

Customers are smart to consider not only vendor claims about their virtualisation 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.

Will virtualisation enhance my management capabilities and ease the workload of my IT staff?

The idea behind storage virtualisation is to improve the effi ciency of your
infrastructure, making storage management easier and more costeffective.

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

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

Others have taken a more federated approach — gluing together hardware components from one vendor with software components from another.

Whichever approach you are evaluating, look for outside validation 1/2 Advertisement of vendor claims — external benchmarks from organisations.

Will virtualisation 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 virtualisation has the potential to do the same thing
for your storage hardware.

Do you want that freedom? If so, ask the virtualisation vendors you are evaluating if they see things the same. Is virtualisation of the complete
disk experience their goal too? Armed with the above storage questions and answers, companies should feel well-equipped to tackle the challenge of evaluating storage virtualisation.

They just might find that they can save time, money and hassle when they make an informed decision about storage virtualisation.