Smarter Storage Simplicity: How New Software-Defined Block Storage Delivers Enterprise Scalability and Performance

David Noy
VP Product Management, Emerging Technologies Division at EMC

Smart enterprise organizations are transitioning from the complex and inflexible data storage systems of recent decades—to a new era of simplicity, scalability, elasticity and performance.

Software-defined block storage based on Server SAN is the important new data center storage model that organizations need to understand in order to bring new efficiency to enterprise application workloads, manage data growth—and exploit a range of new opportunities. The secret to the scalability and performance of Server SAN is based on the very simplicity of its distributed architecture—made possible by the latest intelligent storage management software.

Towards Simpler, Smarter Enterprise Data Storage

Block storage is the trusted engine of most enterprise data centers, running core databases and applications. For a long time, the model for providing enterprise block storage has been the SAN (storage-area network)—using a powerful central storage array based on specialist high-end hardware. This has provided the storage performance that enterprise demands.

But today's enterprise faces a range of challenges in the data center that traditional SAN is struggling to address. Forward-looking enterprise is a simpler and more scalable storage architecture, where storage is distributed across a network of servers and managed using advanced software. This new approach is called software-defined block storage or 'Server SAN'.

The Evolution of Enterprise Block Storage

This ‘software-defined storage’ approach presents applications, admins and users with what appears to be a single unified ‘pool’ of storage—behaving like a high-performance SAN—even though it actually uses multiple separate commodity servers, each with their own directly-attached commodity storage. Server SAN is a major technology trend—Analyst Wikibon predicts overall growth of the Server SAN market to grow 38% CAGR, 2014 to 2020.

So how does the software-defined Server SAN model address the challenges of traditional SAN?

Challenge #1: Storage Simplicity

The typical data center of today is changing—from the smaller, self-contained operation of the past, to bigger, consolidated, and often multi-tenant facilities. The traditional SAN model is too complex and inflexible to cope with today’s fast-evolving data center.

Enterprise organizations looking to bring more simplicity to block storage are now looking to the latest Server SAN solutions—like EMC ScaleIO. The new Server SAN approach is enabling enterprise organizations to scale out block storage quickly, easily and cheaply, adding hundreds of commodity servers over time to provide petabytes of shared storage.

Server SAN is transforming the data center for many enterprise organizations. It makes everything simpler—and better. Rather than managing a complex SAN and a variety of application servers, you can standardize your whole operation on commodity infrastructure for cost reduction, efficiency, scalability and performance.

An advanced software-defined storage solution can also enable data center simplicity and efficiency through the convergence of applications and shared storage on the same servers.

Challenge #2: Storage Scalability

The traditional SAN was developed in a time of much slower data growth. Organizations were usually able to predict their capacity requirements for years ahead with reasonable accuracy. However, as data growth has become faster, traditional SAN has struggled to keep up. A SAN array may be able to 'scale up' in a limited way with the addition of extra storage drives but it can't 'scale out' to the extent needed today.

Software-defined block storage, by contrast, enables you to scale out almost limitlessly. As your requirements change, you can simply add more servers and storage as required to cover both your compute and capacity demands. It’s the same kind of software-defined approach that the biggest web-scale companies have embraced in their giant global data centers to provide the scalability and cost-effectiveness that powers their success.

Challenge #3: Storage Elasticity

Another challenge for SAN is elasticity. While data growth is highlighting the difficulty for SAN to scale, today’s fast-changing business requirements call for the ability to change data storage arrangements on demand. Growing or shrinking a volume of storage is difficult in traditional SAN environments. Capacity planning is a key activity with traditional SAN—to forecast and plan for requirements over coming weeks, months or years. However, nowadays, capacity requirements are something that changes on a daily, hourly or moment-to-moment basis. Planning must happen in real-time—you can no longer predict requirements of your applications in the long-term. Enterprise IT needs the elasticity to add or remove resources, and increase or decrease capacity—at all times.

A software-defined solution like ScaleIO delivers not just scalability, but also elasticity—the agility to make changes to your storage dynamically. If an application no longer needs a particular storage volume, the data center can easily reclaim that storage for other uses. Or if an application needs more storage—right away—Server SAN gives you the ability to change things, easily and quickly. Organizations are discovering greater ability to reassign capacity, create and delete storage pools quickly. As you move data between nodes and pools, ScaleIO intelligently rebalances data distribution across server nodes—keeping everything running at optimum utilization and efficiency.

Challenge #4: Storage Performance

As demand on traditional SAN increases over time, performance tends to fall because it has a fixed amount of maximum available throughput on the storage area network.

Another benefit of EMC ScaleIO’s simple distributed architecture is performance. Each extra server node adds additional network switching and throughput for your Server SAN—scaling up performance linearly to millions of IOPS as required.

With Server SAN, applications have access to directly-attached storage for ultimate performance—as well as to the wider pool of shared storage for almost limitless scalability.

Challenge #5: Storage Resiliency

Although the traditional SAN is designed to be robust enterprise-class storage, its centralized nature brings potential points of failure and data corruption possibilities together in one physical location—the storage array.

A physically-distributed and software-defined storage solution like EMC ScaleIO brings new enterprise-grade protection and resiliency to block storage, with no single point of failure. It spreads and mirrors data safely across multiple storage devices and servers. If a server or storage outage occurs, ScaleIO automatically rebuilds failed blocks and rebalances data to self-heal the cluster.

Challenge #6: Storage Costs

The traditional SAN is an expensive enterprise capex investment. It is based on high-end specialist storage hardware and costly Fibre Channel networking. The complex management of a SAN also requires a lot of manpower costs for the storage admin tasks.

However, in recent years, off-the-shelf or ‘commodity’ storage infrastructure has become powerful enough to rival the performance of high-end specialist SAN—at a much lower cost.

A Server SAN converged approach can bring a range of cost benefits. On the one hand, it may mean you can buy fewer servers—saving on capex costs. On the other hand, it can enable you to do more with your resources. Instead of running 5 compute servers and 5 storage servers, you can have those 10 servers all running applications—and providing shared storage. With ScaleIO, convergence is now a viable option—this interleaving of applications and storage is a more efficient way forward for the data center.

The cost advantages of ScaleIO architecture extend beyond your servers and storage—to the data center networking that connects them. Traditional SAN relies on expensive and complex Fibre Channel networking to achieve low enough latency between application servers and the SAN storage array. This also requires each server to have an expensive HBA network interface. Some Server SAN offerings replace Fibre Channel with similarly complex and management-intensive technologies like SCSI or iSCSI. With ScaleIO, you can use standard low-cost commodity Ethernet networking—yet still achieve SAN-grade performance.

Making Software-Defined Simplicity and Performance a Reality

Enterprise organizations are finding the Server SAN approach to block storage with EMC ScaleIO is enabling new agility and scalability. Service providers using ScaleIO in their data centers are able to meet customer demand for storage quickly and easily.

How do you begin your journey to software-defined block storage and Server SAN? It’s easy to get started—and EMC can help. Organizations that want the reassurance and confidence of a turnkey end-to-end solution can turn to EMC for advanced software with expert support—and a simple pre-configured storage appliance, the EMC VxRack Node.

Get your organization in position to seize the simplicity, efficiency and performance enabled by Server SAN. It’s easy to start with a small deployment—and simple to scale up as your requirements increase.

EMC ScaleIO software is available to try now as a ‘free and frictionless’ download.

Learn more about software-defined block storage, Server SAN and EMC ScaleIO.