The ultimate network-attached storage guide
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Today’s storage managers are facing exponential data growth and the number of NAS technologies and products offered...
to combat data sprawl seem to be growing just as quickly. More and more, data storage managers are looking at the differences between traditional scale-up choices and newer scale-out products.
Here’s a quick overview of the evolving NAS market. As 2012 nears, dominant players position themselves with aggressive acquisitions and new scale-out offerings.
Traditional/Scale-up NAS: EMC and NetApp, a NAS pioneer that released its first system in 1993, continue to dominate the NAS market. Through the first quarter of this year, EMC had a 48.8% revenue share and NetApp was next at 30.8%, according to IDC.
Both EMC and NetApp have proprietary NAS operating systems, but many of their competitors -- including Dell, HP and IBM -- leverage Microsoft Corp.’s Windows Storage Server in traditional NAS. IBM also rebrands NetApp products as its enterprise NAS platform.
Traditional NAS products tend to differentiate largely based on the built-in or add-on software that vendors make available, rather than performance or minimum/maximum starting points, according to Arun Taneja, founder and consulting analyst at Taneja Group in Hopkinton, Mass.
“People buy NetApp because NetApp has the best surrounding software: SnapMirror, SnapVault and the list just goes on,” Taneja said. “That's the No. 1 distinguishing factor on the traditional NAS side.”
Smaller vendors, such as Buffalo Technology Inc., D-Link Corp., Drobo Inc., Iomega Corp. (a wholly owned subsidiary of EMC), LaCie Group S.A., Netgear Inc. and Overland Storage Inc., target small- and medium-sized businesses (SMBs) and departments of large corporations with low-end systems.
Scale-out NAS: Traditional NAS may currently represent the majority of file-based storage systems in business environments, but industry analysts expect the situation to flip in favor of scale-out NAS over the next few years.
“In the end, everything will be scale-out to some extent,” said Andrew Reichman, a principal analyst at Forrester Research Inc. in Cambridge, Mass. “File data growth is at a very high rate for most companies, and having to buy a single box and predict how much capacity you’re going to need for the next five years is a real challenge. Nobody wants to do that.”
Major storage vendors have made scale-out NAS a prime acquisition target. In the largest deal, EMC paid approximately $2.25 billion in late 2010 to purchase Isilon Systems Inc. and gain a foothold in scale-out NAS.
The most recent deal was Hitachi Data Systems (HDS) Corp.’s acquisition of its OEM partner BlueArc for about $600 million. HDS rebranded BlueArc’s products for years as Hitachi NAS (HNAS). BlueArc had sold its enterprise-class Titan Series for more than eight years and its midrange Mercury Series since mid-2009. Regardless, some analysts question the true scale-out nature of the BlueArc systems.
“BlueArc’s approach is less about clustering and more about really big, really fast boxes that can be paired,” Reichman said. “The clustering they talk about is really a two-way cluster more than an n-way cluster.”
NetApp had a big head start on its NAS archrival, EMC, with the purchase of Spinnaker Networks Inc. in November 2003. But the fruits of the merger didn’t start to take shape until the 2006 release of NetApp's Ontap GX and, more significantly, with the 2009 release of its Data Ontap 8 operating system. NetApp still isn’t a true scale-out architecture, but Data Ontap 8.1, expected by year’s end, aims to integrate more of the enterprise-class features and functions from NetApp’s traditional NAS with the cluster mode.
HP’s mid-2009 deal for Ibrix produced its X9000 family of scale-out NAS products, and that same year, Oracle Corp.’s purchase of Sun Microsystems Inc. led to the ZFS OpenStorage Appliance that Sun marketed as its 7000 series.
Dell’s February 2010 purchase of Exanet Ltd.’s assets contributed to its PowerVault NX3500, which launched in April 2011. Dell also added scale-out NAS capabilities to its EqualLogic FS7500 and is working on integrating its scalable file system into the SAN platform acquired from Compellent Technologies Inc.
IBM based its Scale Out Network Attached Storage (SONAS) product, launched last year, on its General Parallel File System (GPFS) and the Scale-Out File Services (SOFS) offered through IBM Global Technology Services.
Panasas Inc. heads the list of vendors focused on HPC. Other HPC specialists include Terascala Inc. and Xyratex International Inc. DataDirect Networks Inc. also plays in the space when its arrays are bundled with the open-source Lustre distributed file system or IBM’s GPFS.
Additional vendors with targeted offerings include Facilis Technology Inc., which focuses on media and entertainment; Gridstore Inc., Reldata Inc. and Scale Computing Inc., which cater to small- and medium-sized enterprises (SMEs); and Nexenta Systems Inc. NexentaStor, Quantum Corp. StorNext and Gluster Inc. Virtual Storage Appliance that have file systems that serve as the underlying technology for scale-out NAS systems.
One of the main distinctions between scale-out NAS products is whether they tilt toward throughput to better handle large files or IOPS for large numbers of small files.
“The instant you know the answer to that question,” Taneja Group's Taneja said, “you know which applications it will do very well in and which applications it will not be a good product for.”
Taneja noted that Isilon started with throughput-centric systems that performed well with large files such as rich media. But, more recently, Isilon worked to balance its architecture and improve its IOPS performance, he said. The company now offers three product lines, each geared toward a different type of workload.
Another thing to look for in scale-out products is their support for the Common Internet File System (CIFS), the file-sharing protocol in Windows-based systems, noted Randy Kerns, a senior strategist at Evaluator Group in Broomfield, Colo.
Kerns said that scale-out network-attached storage systems in HPC were predominantly Unix- or Linux-based, and may lack a native CIFS implementation. Without native CIFS, users might experience problems with permissions handling, security and Active Directory integration, he said.
Scale-up and scale-out: Some NAS vendors, such as Dell and HDS BlueArc, claim to support both traditional/scale-up capacity and scale-out performance configurations, with a single namespace to ease management.
“Scale-up systems can’t typically scale out, but scale-out systems can scale up,” said ESG’s McClure. She said the transactional file I/O capabilities in EMC's Isilon S-Series qualify those products as scale-up and scale-out. Isilon also sells an X-Series for large capacity needs and a NL-Series focused on nearline storage.
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