Virtual reality
Virtual reality
Or is it? Issues such as scalability, affordability and proprietary interests must be resolved before storage virtualisation can really fly. Stuart Finlayson reports.
The word 'virtual' is, according to the dictionary, used to describe something "existing or resulting in essence or effect though not in actual fact, form, or name."
I refer to this because, by natural extension, virtualisation would seem to be concerned with an action that makes something appear as something it is not. So what does that make storage virtualisation?
The concept of storage virtualisation within IT networks has been floating around for some time now, but has only really been pushed as a major strategic initiative by the leading vendors in the last few months.
A degree of confusion exists in the marketplace as to what storage virtualisation actually is and what the benefits are for the user. This is largely down to the fact that storage virtualisation can be achieved at different levels of the storage infrastructure, and if a customer is to ask a vendor what storage virtualisation is, that vendor is likely to define it according to its particular area of expertise and what it can offer the customer. This could mean that if a customer talks to a range of storage providers, as is the norm when one is considering spending a lot of money, they may be left with an array of definitions and options, leaving them none the wiser as to what solution is best for their organisation.For example, storage virtualisation can be administered at the host level, switch level, or storage array level.
Despite the term still being hostage to vendor interpretation to a certain degree, the message of what storage virtualisation should be all about is getting through to the vendors, at least in some quarters. And what is prompting this epiphany? Something as simple as dialogue with customers.
Take Dimension Data for example. Rosemary Stark, national business manager for Dimension Data Australia, describes how her definition of storage virtualisation has been shaped by such discourse.
"In talking with many customers worldwide, I found that they wished to move away from the worry of what their storage is or where it might be physically located. Instead they wished to define their storage in terms of three requirements: how much do they need, what performance do they need and what availability do they need, while being assured of maximum utilisation of their assets. This to me is what storage virtualisation truly is, irrespective of the technology used to deliver it."
Essentially, storage virtualisation is gaining momentum in enterprise IT management because the ever increasing volume of data that has to be managed, coupled with the increasing complexity of the back-end of storage systems, is crying out for something that helps IT managers simplify the management and storage of data, something which storage virtualisation purports to deliver.
In a recent posting on its corporate website, designed to demonstrate why it had chosen to highlight virtualisation, HP described what virtualisation brings to the party in clear terms.
"Traditional IT environments are often silos where both technology and human resources are aligned around an application or business function. Capacity is fixed, resources are over-provisioned to meet peak demand, and systems are complex and difficult to change.
"With a virtualised infrastructure, people, processes and technology are focused on meeting service levels, capacity is allocated dynamically, resources are optimised, and the entire infrastructure is simplified, flexible and more capable of adapting to change."
Popular opinion within the industry suggests that the wholesale virtualisation of the storage infrastructure is on its way, so it is important that say, for example, an organisation was about to embark on architecting or re-architecting its SAN, that it ensures the resulting SAN design will be able to efficiently and effectively support virtualisation technology.
"Virtualisation will become more important in the future for small and large SANs alike," predicts Andrew Smallridge, a consulting engineer with Cisco Systems and a specialist in Cisco's Storage Networking Technology. "Network virtualisation is a critical component of the storage utility model delivering the ability to effectively and efficiently implement storage on demand based on enterprise policy with the network elements automatically being configured to deliver the appropriate class of service across all elements of the SAN."
That is not to say that the proponents of the storage virtualisation model (namely the vendors) are without their obstacles to negotiate before users' entire storage infrastructures can truly sing from the same hymn sheet. Chief among those obstacles is the protection by the vendors themselves of their proprietary interests, which they will have to accede to loosening their grip over so that other companies can tailor their part of the storage infrastructure according to what's contained within the nuts and bolts of the other components of the storage infrastructure. Otherwise, virtualisation cannot be achieved.
"Today, this is a challenge," admits Cisco's Smallridge. "The easiest networks to deploy virtualisation are homogeneous SAN environments-that is, those least likely to benefit from the technology. If we examine other areas of SAN technology we can see that storage vendors are losing their stranglehold over customers and that it is not uncommon to see data centres with arrays from different vendors despite the interoperability challenges this does present. Network Virtualisation will actually help customers in this situation by enabling functions, such as mirroring between arrays from different vendors. The reality today is that these vendors, via the "certification" tool (weapon?) determine who is allowed to play in their space." Weapon? Controversial!
DiData's Stark agrees that vendor self-interest is still prevalent, but says that customer power is slowly changing this around, forcing vendors to work more co-operatively."From the demand by consumers that SANs and storage virtualisation solutions in general be much more inclusive and co-operative, we have seen that vendors who traditionally have competed have formed alliances to answer these requirements. However, with different agendas and many alliances within the industry, there is still some way to go and a need for skilled integrators to work with the end customer and varied vendors to deliver a workable solution."
Another element pushing the collaborative approach to storage, according to Tim Smith, marketing manager, ANZ, Hitachi Data Systems, is the creation of industry standards."With a greater push for standards across the industry (such as SMI-S) we will begin to see the proprietary approach of the past fall away."
What can storage virtualisation achieve?
"The main selling points are cost reduction, improved asset utilisation and simplification. Customers of all sizes are seeing the incremental benefits of implementing this strategy. They are implementing each tactical step in this strategy and using the cost savings to implement the next step." So says Clive Gold, marketing director, EMC. But what are the components of a successful virtualisation strategy? Let's examine those.
1. Mixing and matching storage elements-This is the ability to combine storage devices from multiple vendors in the overall SAN, enabling the storage administrator to select best of breed, as determined by the customer's own criteria, for each class of storage.
2. Application testing / data migration-The replication of data across storage platforms using storage from different vendors or different storage devices from a single vendor. For example, a database located on a high end array could be replicated to low cost disk for use with testing and debugging applications.
3. Centralised administration-The ability to provide centralised configuration and management of storage resources. In a heterogeneous storage environment, a single set of tools is used to allocate storage to all end devices irrespective of the array vendor or vendors in the network.
4. Simplification of host configuration-In heterogeneous environments supporting multiple operating systems and HBA, it can be challenging to maintain network wide compliance to certification for all devices attached to the SAN. Currently, when an upgrade is necessary, the roll out is dictated by the ability to rollout a compliant (tested) configuration across all systems and platforms simultaneously. Networked storage applications will enable the removal and/or simplification of the drivers installed on each host. It has the potential to remove a complete layer from the certification dependency.
What about the cost?
If not always the most important factor in every acquisition, cost is usually certain of a least a podium finish when weighing up the most important aspects of an implementation. While a company may have to bear the initial financial brunt of virtualising its storage infrastructure, research indicates that this will be well worth it in the longer term.
Gartner, for instance, estimate that by 2008, enterprises that do not leverage virtualisation technologies will pay up to 40 percent more in acquisition costs, and roughly 20 percent more in administrative costs than enterprises that leverage virtualisation technologies, it would seem on the face of it that the question of whether to employ a storage virtualisation strategy would be something of a no-brainer for IT managers.
Poorly utilised resources can be put to work more effectively, with previously disparate, siloed parts of the IT environment pooled together to meet the changing needs and priorities of a business.
"There is certainly a lot of enthusiasm for what storage virtualisation can deliver, and many CIO's and IT managers are beginning to undertake audits and other preliminary work examining this," says Gopi Jayachandran, business development manager, Storage Services, HP Australia. "In five years time, storage virtualisation will be a critical part of most enterprise organisations."
Storage virtualisation should not-as HDS' Tim Smith points out-be regarded as something of a panacea in itself by IT managers, as they still have a very important part to play in laying out the groundwork prior to moving over to a virtualised environment, not to mention the ongoing management of that infrastructure once it is up an running."It is important to remember that virtualisation is not a single product, or set of products, but a methodology. A well documented and thought out virtualisation methodology will benefit a company's backup and recovery strategy through simplification and consolidation. However, an unplanned point solution will not necessarily be so kind."
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