Harvest The Benefits Of Storage Virtualization

At a recent industry conference, a senior manager from a very sizeable IT organization took me to one side to ask -- quietly! -- whether I thought thin provisioning "is okay? It safe to try?" Really? Maybe you're surprised -- but I can tell you that every time we research such tools at ESG we are amazed at how far the adoption (perhaps I should say "active use") is behind what operational and financial logic would seem to dictate.

For a leading-edge industry, IT can suffer from some strange lags: I don't have a cool name for it, but the adoption lag (maybe that'll have to do?) is interesting. It's the time that elapses between the market generally acknowledging that some feature or tool is a good thing and the point at which most users have actually moved to adopt it.

Of course some delay is inevitable because of the irregularity of buying cycles, and perhaps also because of some natural cynicism (let's be kind and say pragmatic conservatism) when you're dealing with the organization's crown data jewels. But there's another thing at play too, I believe: the adoption lag gets elongated because of a tendency for us all to shift our sights to the next bright, shiny object … even before we've fully benefited from the potential in the prior wave. These days there's so much talk of clouds and software-defined-everything that the simple value of maximizing the efficiency of storage infrastructures via extensive virtualization can get overlooked. This article is a reminder to look in the storage mirror (no pun intended) and check that you are not missing out on what can be fairly long-hanging fruit.

Growing Infrastructure Efficiency

Organizations are struggling to manage the combined weight of rapidly proliferating server farms and the commensurately growing, dedicated storage pools. Server farms of hundreds and even thousands of individual machines have proven to be nearly impossible to manage … at least effectively and economically. End users are seeking solutions to these growing complexities and inefficiencies. The value of continually procuring individual components is diminishing, and the contemporary opportunity to implement integrated computing and storage platforms is well timed. "Integrated IT infrastructure" is certainly all-the-rage right now (often this is being called convergence) and is a direct result of the success of virtualization of servers, networks and storage.

Achieving overall infrastructure efficiency has never been easy, but one good start is to take the onus off the shoulders of end users to figure it out themselves. Server virtualization has been the catalyst for the evolution of the compute infrastructure. Consolidating multiple application workloads on far fewer hardware platforms has revolutionized the ability for users to be efficient in terms of "compute-ability." The benefits are well documented and significant: Server hardware for many users has been reduced by 50%, 60%, even 80%, enabling both capital and operational cost savings.

[ Learn how to make the most of virtualization. Read Why Flash Storage Excels In Virtual Environments. ]However, the aggregation of server workloads has put tremendous stress on both networking and storage. The challenges in storage are extreme, with industry measures and anecdotal evidence consistently confirming that anything from 40% to 50% or more of disk capacity sits idle (i.e., wasted), locked behind a particular server. This can even happen while another storage "pool" is running out of capacity. Just buying more storage is clearly (at best) inefficient, and (at worst) a sheer waste of resources and a poor business decision when unused capacity is sitting idle elsewhere in the same environment. In some cases, storage has thus become an unwanted poster child for inefficiency, driving up acquisition costs, consuming data center floor space and energy, and increasing management time.

Harvesting The Benefits of Storage Virtualization

Storage virtualization offers benefits to the storage infrastructure that are similar to those that server virtualization delivers on the compute side. In other words, storage virtualization is breaking the mold so that the true value of data services is no longer limited by hardware characteristics. Instead of dedicated pools of storage capacity that cannot be shared, a virtualized storage pool can enable:-- Reclamation of stranded storage capacity: This makes unused capacity available to any servers, users or applications accessing the (now) general pool. In addition, when storage is no longer needed, it becomes part of the pool again and can be used elsewhere.

-- Consolidated storage management: Applying to all storage resources, this can eliminate multiple tools and processes for different types of storage arrays and media. Consolidating storage management under one umbrella makes the environment easier to manage and provides less opportunity for both human and administrative errors.

-- Advanced storage management features: These can extend the useful life of storage devices, as well as maximize the return on investment and potentially prevent, or at least delay, additional storage purchases. For example, in a virtualized storage environment, functions such as snapshots, remote replication and thin provisioning, which may come bundled with a storage system, can be shared across arrays that don't have those features.

-- More energy-efficient operations: This can be achieved by using storage virtualization to improve disk utilization, which in turn reduces the number of physical machines while simultaneously reducing data center floor space, power and cooling requirements.

-- Non-disruptive data migration: While data migration is a core concept in executing a pragmatic and sensible tiered storage strategy, it has also long been seen as one of the most common and disruptive storage tasks. In traditional storage environments, it's not at all uncommon for users to decide that the pain is enough to prevent them from enjoying the gain! But with storage virtualization, data can be moved non-disruptively (and often even automatically) between storage tiers, further optimizing hardware infrastructure costs.

-- Reduced capital expense and total cost of ownership for storage: This is all-but guaranteed with the implementation of storage virtualization. A virtualized storage environment replaces the fragmented, dedicated DAS, SAN and NAS topologies (which -- in traditional storage worlds -- invariably operate with separate storage resources and often a unique set of management tools) with a centralized and more flexible storage pool.

Virtualized storage is essentially accomplished in the same way as the virtualization of servers: The physical controller hardware and disk resources are logically separated from the data services. With virtualized storage, a pool of flexible, consolidated resources with a common management interface is built using capacity from multiple arrays that can have different specifications and software features, and may even have come from different vendors. Because storage is not dedicated to any specific server or application, it creates a much more flexible and responsive environment while also permitting increased utilization rates.

In addition, while users may be able (using VMware vMotion or some such tool) to move a running application between servers, traditional, fixed storage won't automatically go along with the change, thus rendering it all-but pointless. Virtualizing the computing element without virtualizing the storage as well precludes the complete agility and true utility-like resource provisioning that most IT shops are looking for; if the storage cannot match what the servers can do, then the anticipated service levels cannot be met.

The economic and operational value of virtualizing storage is clear. For decades, most organizations have had a fairly cavalier attitude towards storage. It's not that IT wasn't aware of its rising costs -- it's more that it didn't see any other ways to address the problems with which it was faced. But virtualization has changed all that, demonstrating a way to operate with greater efficiency. Users that do not enthusiastically embrace it are essentially wasting money, while at the same time missing out on operational improvements that can only be gained in fully virtualized environments.

It's worth a few minutes to check that you're maximizing your potential storage virtualization benefits and not falling into the adoption gap.