The demand for storage capacity is surging, fuelled by the growth of the Internet and the rising demand for online access to data. The ability to move and access data has become a mission-critical capability for every enterprise. CIOs are under increasing pressure to improve data management and reduce total cost of ownership.
The predominant strategy is the move toward networked storage. The storage industry is driving this move with a multitude of innovative storage networking technologies that will add significant capabilities to corporate network architectures. Networked storage is making the revolution in data storage inevitable – and the statistics on storage networking bear that out.
Storage networking, whether network attached storage (NAS) or storage area network (SAN), has become essential to mission-critical IT environments. IDC estimated in a July 1999 report that the storage market in Canada could grow to about US$4.3 billion by 2003, of which about US$1.5 billion is external storage. Moreover, networked storage solutions are driving all the growth in the Canadian market and are predicted to account for half of enterprise storage revenues by 2005.
The numbers are positive, but in the minds of IT executives the projected growth for networked storage doesn’t paint the full picture. CIOs need some clarification of specific issues in networked storage. This article looks at the capabilities and benefits of networked storage, as well as the debate over network attached storage (NAS) versus storage area network (SAN) technologies. There is a strong belief that the future of networked storage will see a convergence of NAS and SAN, a union that will provide a stronger unified solution to the NAS/SAN debate and pave the way for the ultimate goal: open storage networking.
The Benefits of Networked Storage
Network-attached storage differs considerably from the traditional server-attached storage model that dominates the Canadian storage sector. For CIOs, the burning question is: what are the major benefits of an investment in a storage network architecture? The answer is threefold. Once the decision is made to grow, IT executives can architect shared storage pools that can scale seamlessly. Second, these networks will greatly reduce restore and back-up times by leveraging on-line archives and new types of secondary storage media. Finally, IT managers enjoy far greater manageability of data, because they control their databases from a single central point. This combination of scalability, faster recovery and backup, and manageability inevitably reduces the total cost of ownership of data storage. However, before an IT executive can make a decision to move towards networked storage, the executive should explore the debate that rages between NAS and SAN.
Narrowing the Gap Between NAS and SAN Technologies
A NAS system is essentially a plug-and-play storage solution based on standard IP networking architecture and attached to a local, metropolitan, or wide area network. Its design eliminates server bottlenecks on heterogeneous networks by providing cost-effective storage and file-sharing. SAN is best described as the vision of an open, scalable, fibre-channel architecture that interconnects storage systems, backup devices, and servers. It absorbs LAN traffic to improve network performance.
In network attached storage, a single central file system resides in the architecture of the NAS appliance and controls data storage. In a SAN, the file systems are part of the operating systems that reside on multiple servers. Multiple servers implies that data must be stored in a variety of file systems and formats, which make true data sharing a challenge.
Both NAS and SAN offer significant performance advantages over traditional server-attached storage. Despite this, CIOs often see NAS and SAN as competing or mutually exclusive technologies. The truth is, in a networking environment SAN and NAS are complementary and interoperable, and each has its place in corporate network architectures. For CIOs to understand where these technologies are headed, we have to examine another trend in storage networking technology – convergence.
Why SAN and NAS Are Destined to Converge
CIOs are in search of the ideal storage networking solution, but they also need to improve the operating costs of their business solutions. They will be among the first to drive the convergence of NAS and SAN. Distinctions between NAS and SAN will eventually dissolve, bringing the two together as parts of a single solution. Here are some of the issues currently affecting NAS and SANs: