Aggressive acquisition and retention of data, the acceleration of business analytics and impending retention policies and regulations in the Middle East have driven the growth of unstructured data within the organization. The need to rapidly scale storage while permitting maximum flexibility has given rise to a new storage methodology. Scale-out storage, as opposed to scale-up storage, focuses not only upon how quickly a storage platform can add capacity but also upon how to do so while ensuring that the performance scales linearly as well.
What is Scale-out Storage?
The defining characteristic of scale-out storage is the fact that a single scale-out storage system is composed of many independent server nodes forming a loosely coupled distributed storage system. Thus, scale-out refers to the idea that the capacity and performance of the system may be increased by "scaling it out," that is, by adding additional nodes. . Because each of the nodes in a scale-out storage system brings with it a balanced set of CPU, memory, disk and network interfaces, scale-out systems are known for their ability to scale linearly, without degrading performance as incremental nodes are added. This is in contrast to traditional NAS storage wherein capacity is added by scaling-up or by adding additional resources such as a disk, within the device itself.
The growing interest and adoption of scale-out storage has been driven not only by its performance characteristics but also by the outstanding economics offered by the technology. IT executives continue to be asked to do even more with even fewer resources forming solid ground upon which a case for the deployment of scale-out storage can be made.
Cost Implications
Scale-out storage offers a number of advantages relative to traditional NAS. To start with, scale-out storage environments are built using off-the-shelf servers and disk, while traditional NAS is typically based on proprietary hardware components. This has significant cost implications, as the cost of commodity components is driven down by marketplace pressures, while vendors of proprietary systems fight to retain the premium they place on their offerings.
Thanks to the flexibility of scale-out storage, systems can be scaled by adding new nodes and growing capacity over time. The scale-out storage model also supports the repurposing of hardware. For example, as organizations adopt virtualization for consolidation, decommissioned application servers can be added to new or existing storage environments. In contrast, traditional NAS systems scale-up through the addition of expensive hardware which encourages over-provisioning that may prove to be wasteful if it takes longer than estimated to reach capacity targets.
Operational Expenditure
In addition to the sheer number of cost advantages that scale-out storage offers over traditional NAS storage, there are several reasons why scale-out storage is more attractive from an operations perspective as well.
With monolithic NAS, each appliance is individually managed which is why operational costs rise proportionally to the size and scale of the storage environment. A key operational characteristic of scale-out storage is the ability to unify disparate servers and their disks into a single global name space. By virtualizing the underlying storage infrastructure and automating its management, scale-out storage decouples management costs from the size and scale of the physical storage system.
Ensuring high levels of data availability can be a perpetual challenge for administrators. Beyond the additional capital expense required for hot/warm/cold standby systems, keeping operational procedures fresh and ready for use when disaster strikes can require a significant investment of both resources and mind-share. With scale-out storage on the other hand, characteristics such as high availability and disaster recovery are inherent to the storage platform. In scale-out environments, data availability is ensured via automated local and remote replication, and happens transparently according to policies set by the user.
Strategic Factors
While capital and operational cost reductions can positively impact savings, any new technology should always be primarily evaluated for its ability to transform processes for greater business agility. Here too scale-out storage proves its worth.
By forming a single, unified, highly elastic storage pool that is compatible with a wide variety of applications, businesses become positioned to innovate quickly and respond to marketplace shifts without the burden of establishing a new storage environment for each new initiative.
Furthermore, enterprises deploying scale-out storage are positioned to unify access to data from many sources and make that data broadly accessible to a wide variety of applications and users, fostering high levels of insight and responsiveness within the enterprise.
Conducive to the Cloud
The shift towards cloud computing has many implications for storage. While there remain impediments to wholesale migration of enterprise systems to the public cloud, these barriers are lowered every day.
Cloud computing models promise to deliver business agility, and in order to take advantage of this possibility, it is imperative that enterprises consider the cloud readiness of each incremental technology they adopt.
Because of its ability to unify disparate storage systems into a single unified environment, scale-out storage is ideally suited for the cloud. Cloud computing allows users to 'rent' compute and storage resources from third-party cloud providers, and has become a popular strategy for reducing capital expenditures. Software-based scale-out storage is easily deployed in cloud computing environments, without requiring changes to applications. Scale-out storage running in the cloud is thus an effective way to completely eliminate the capital costs associated with traditional NAS storage.
Given the software-based nature of scale-out storage systems, users are able to readily migrate instances of this to cloud computing environments in order to increase or augment capacity or reduce costs - without rewriting applications or needing to learn a new system. As a result, scale-out storage users are able to more readily take advantage of cloud computing than users of hardware-based NAS systems.
Thanks to dynamic requirements, increasing virtualization and the advent of Big Data, the days when IT organizations could carefully plan their storage needs are over. Faced with tight budgets, IT departments can no longer throw additional storage hardware at the problem hoping for a quick fix. Storage systems need to be intelligent enough to allow organizations to bring extra capacity on line in ways that don't end up slowing application performance. Scale-out storage accounts for this and the host of benefits it brings can greatly contribute to the overall competitiveness of the enterprise.
© Zawya 2012
