How to: Choosing an SMB NAS

The network-attached storage (NAS) market is one of the most dynamic sectors of the IT market with compound annual growth rates set to surpass 20.7 per cent from 2010 to 2015.

Research firm Gartner said the NAS market registered a remarkable 36.2 per cent revenue increase in 2010.

This remarkable growth represents a shift from general purpose file servers to NAS systems.

This shift will impact direct-attached storage, and to a smaller degree, Fibre Channel storage area network (FC-SAN) attached storage.

With the focus on simplicity, file storage consolidation has gone beyond the enterprise environment to reach the small to medium business sector (SMB).

Gartner analyst Pushan Rinnen said the increased demand in file storage is due to the ever increasing volumes of digital content.

Mr Rinnen said other major growth drivers include storage architectural changes triggered by virtualisation, and continuing vendor innovation.

While a lot of SMBs are still using general purpose file/print servers because of familiarity with traditional systems, he said this is changing as the mid-market increasingly looks to NAS appliances.

On the vendor side, there has been a lot of innovation with the focus on deduplication, scalable file systems, automated tiering and automation of storage management.

To help SMB’s choose a NAS product, this feature outlines the market basics including the different product segments, technologies and providers.

What are NAS products?

NAS products are specialised file server/storage systems providing file-sharing services for computing systems (clients or servers) attached to a Local Area Network (LAN) or Storage Area Network (SAN). They use one or multiple file protocols, such as the NFS for the Unix/Linux environment and the CIFS for the Windows environment. They include a file system and frequently an Operating System (OS) streamlined for file serving.

Stand-alone NAS – These NAS products combine the server head with internal hard disk drives or direct-attached HDD storage arrays for usable storage. They are sold as an integrated NAS storage system. Unified storage supports both NAS and SAN access protocols. Interestingly, stand-alone NAS accounted for 90 per cent of the total NAS market in terms of revenue in 2010, according to Gartner.

NAS gateways – In contrast to stand-alone NAS, a NAS gateway is only the server head component of a stand-alone NAS device with no direct-attached usable storage. Its internal disk drives are used for OS image, not for actual data. Usable storage is provided by traditional SAN storage arrays via a SAN (either FC or iSCSI) switch.

Traditional NAS gateway vendors include EMC, NetApp, IBM and Hitachi Data Systems. There are a number of new vendors entering the market. For example, HP is working on NAS gateways for 3PAR while Symantec’s FileStore is a software solution that runs on x86 servers to function as NAS gateways. Dell has also announced its NAS plans for the EqualLogic line. Some NAS gateways, like those from NetApp, also function as a storage virtualization appliance with block-access protocols that are used to leverage more advanced functions than those available in selected back-end SAN storage.

Over the page: The NAS products on offer

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There are a broad range of products available depending on the size of your business. Here is a breakdown of market segments which outlines how NAS products are used, their main features and pricing.

Consumer NAS – Consumer NAS is derived from low-end traditional NAS, but is evolving into a very different product that focuses on the converging digital home. This device is defined as a centralised, multifunction storage system for the home network. It can function as a file server with remote access to multiple PCs and media players, a print server, a media server, a backup and archive system, and temporary storage for Internet downloads or video on demand.

Vendors in this segment are scaling up their systems to house 12 bays and support iSCSI and virtual server environments broadening the product use for different applications.

SMB NAS – This refers to entry-level NAS storage systems ideal for the small business. It excludes products in rack-mount form factors. Their feature functions are geared more toward a business environment, rather than a home, and include the support of Microsoft Active Directory and Access Control List. Midmarket NAS – This segment deals with small businesses and branch offices of midsize and large organisations. These environments have widely deployed general purpose file/print servers using direct-attached storage (DAS). They are often installed by resellers as SMBs have limited in-house resources. The average price range for these products is $5,000 to $24,999.

Midrange stand-alone NAS – In this segment of the market Gartner uses two price bands - $25,000 to $49,999 and $50,000 to $99,999. These two price bands together grew 49 per cent in revenue in 2010, according to Gartner. In this segment NetApp, EMC and IBM captured a combined market share of 80 per cent in revenue last year.

Rinnen said user demands for the midrange stand-alone NAS segment will be strongly influenced by sales of unified storage, which supports NAS and SAN simultaneously out of the same system. “Important use cases for this segment include directories, file sharing, host virtualization and easy, affordable backup/recovery,” he said.

High-end stand-alone NAS – The average selling price in this segment of the market begins at $100,000 or more so we are talking about a significant investment in storage. In 2010, Gartner said revenues for this segment grew by more than 51 per cent. The focus in this high end of the market is on unified storage for data centre consolidation, as well as scalable NAS environments.

Technology trends

Use of commodity operating system platforms is leading to an increasingly blurred line between NAS and Storage Area Network (SAN) storage arrays. Today, vendors have added array capabilities and both iSCSI and FC support to their NAS devices. At the same time array vendors have added NAS file sharing capabilities to their arrays. This merging of the two types of storage device is likely to continue as arrays and NAS devices become increasingly software driven.

There are even arrays that run next generation file systems such as Sun’s Zettabyte File System (ZFS). Building on a file system like ZFS means that host volumes are created as virtual volumes contained within the ZFS, with the array simply mapping physical storage to the file system.

Standards

Prior to purchasing any storage product it is important to buy according to industry standards and best practice. Performance benchmarks for products are also useful.

Gartner analyst Nik Simpson suggests using an independent source such as the Storage Performance Council. “For too long, useful storage benchmark results have been almost impossible to obtain, with vendors providing numbers based on workloads bearing little resemblance to real-world situations,” he said.

Moreover, when it comes to industry standards for storage management, Simpson said the Storage Networking Industry Association (SNIA) is the only game in town.

“Vendors hate doing side by side tests with rivals and customers simply cannot spare the time. That leaves standard and independently audited benchmarks as the only way for customers to compare performance,” he said. Therefore, an informative resource for potential buyers is SNIA’s website.