In storage, scale-out systems are becoming a popular option to deal with rapid data growth. File data is growing the fastest, making network-attached storage (NAS) the most popular type of scale-out storage. Clustered NAS systems that fit the “scale-out” tag are targeted at processing heavy applications such as “big data” analytics and large file environments.
Storage vendors differ over the best way to architect a scale-out network-attached storage system, but the largest vendors and many smaller ones have pushed into the market. Most scale-out NAS systems use individual device nodes, which can be commodity servers or proprietary devices. As interest in scale-out systems has increased, well-known storage vendors such as Dell Corp., EMC Corp., Hewlett Packard (HP) Co., Hitachi Data Systems (HDS) and NetApp Inc. have acquired technology to offer their own scale-out NAS products. IBM OEMs NetApp’s technology while it develops its own.
The scale-out NAS market has come a long way from its technical computing roots and now offers enterprises the ability to handle the pervasive unstructured data growth and server virtualization expansion many administrators are finding hard to manage. Growing capacity, computing and connectivity lessens the risk of overprovisioning for performance or capacity. Many of today’s scale-out NAS systems also have enterprise data services and increased data protection.
Let’s take a look at the scale-out network-attached storage market and its vendors.
The usual suspects in the scale-out NAS market
EMC made the most expensive move in the scale-out NAS market with its $2.25 billion acquisition of Isilon Corp. in November 2010. At the time, Isilon was seen by many as the big fish in the relatively small scale-out NAS market. Like many of its competitors, EMC chose to acquire scale-out technology rather than develop it in-house.
"Customers are really valuing simplicity in their data centers. They want to be able to scale out the storage environment in a very simple fashion. They don't want any complexity in that architecture."
Nick Kirsch, EMC Isilon's Director of Product Management
With EMC's large sales department and channel program, Isilon is still the big tuna. "Without question, Isilon is the scale-out market leader," said Arun Taneja, consulting analyst and founder at Hopkinton, Mass.-based Taneja Group Inc.
According to Nick Kirsch, EMC Isilon's director of product management, Isilon was built from the ground up as a scale-out system. He said other systems have merely added sharing layers on top of a traditional storage file system.
"Customers are really valuing simplicity in their data centers," Kirsch explained. "They want to be able to scale out the storage environment in a very simple fashion. They don't want any complexity in that architecture."
NetApp acquired scale-out NAS technology when it purchased Spinnaker Networks Inc. in February 2004. While EMC acquired a complete business line and product portfolio in Isilon, NetApp bought Spinnaker for its intellectual property and integrated the Spinnaker technology into the NetApp Data Ontap operating system used throughout its FAS storage platform. NetApp began offering clustered storage configurations in 2007, and Version 8 of its Data Ontap operating system (OS) married the scale-out network-attached storage capabilities of its Data Ontap GX OS with the data protection features of Data Ontap 7G.
Dell acquired its scale-out technologies when it purchased the assets of Exanet in February 2010. Dell renamed the old Exanet file system as the Dell Fluid File System. That file system is available with Dell’s PowerVault NX3500 and EqualLogic iSCSI storage products. Dell is also integrating the NAS file system with its Compellent Fibre Channel storage-area network (FC SAN) platform.
"We’re bringing unified capabilities to our existing families of storage," said Mike Davis, director of strategy planning for Dell’s NAS. "We can take a physical NAS device or a cluster of NAS devices, and put them on any of the underlying SAN products.”
HP's scale-out NAS technology came via the 2009 acquisition of startup Ibrix Inc. The Ibrix technology is now part of the HP StorageWorksX9000 series, which scales to 16 PB. HP had acquired clustered file server software provider PolyServe Inc. in 2007, but phased out its use of PolyServe technology after buying Ibrix.
HDS acquired OEM partner BlueArc Corp. and its scale-out NAS technology in September 2011. BlueArc’s SiliconFS file system supports 16 PB total capacity and 4 million objects per directory with storage load balancing and a virtualization toolset. The Titan series is aimed at high-performance enterprise applications, while the Mercury line is more for midmarket environments.
IBM sells a Scale Out Network Attached Storage (SONAS) system built on its own General Parallel File System (GPFS). SONAS scales to 21 PB and 256 file systems, and is targeted at large enterprises and cloud providers. Consultant Taneja said he expects IBM will eventually reduce its reliance on NetApp by developing the SONAS brand.
Other vendors target vertical markets
There are other vendors selling NAS, usually to more targeted verticals such as high-performance computing (HPC), energy companies such as oil and gas developers, media and entertainment firms, and scientific organizations.
Panasas Inc. targets its ActiveStor parallel storage system to technical computing environments in energy, finance, manufacturing and other research markets. Its rack-mount blade architecture consists of self-contained chassis that hold up to 11 storage and director nodes for compute, capacity and file management. The chassis also includes up to two 10 Gigabit Ethernet blade switches. ActiveStor stores files as objects for performance and reliability.
DataDirect Networks (DDN) Inc. goes after the media and entertainment, cloud provider and supercomputing markets with its GridScaler and ExaScaler products. In April 2011, DDN introduced its NAS Scaler multiprotocol enterprise platform for more mainstream NAS shops. NAS Scaler supports up to 16 nodes and 2 PB usable capacity per cluster. It also has some advanced data protection features, such as automated storage tiering, snapshots, mirrored volumes and asynchronous replication.
Scale Computing targets midrange organizations with its Intelligent Clustered Operating System (ICOS). Unified storage is offered with its S-series product line for midmarket environments, while the firm's M-series line is for high-performance database and virtualization needs. ICOS’s data protection features include thin provisioning, snapshots and remote copy-on-write replication.
Quantum Corp.’s StorNext appliances are also aimed at media and entertainment, HPC and energy verticals. The StorNext Q-series features dual-active controllers and automatic I/O path failover. The different Q-series models can scale from 7.2 TB to more than 1 PB raw capacity. In 2011, Quantum added a StorNext Archive Enabled Library for midsize companies with a proliferation of massive files.
Symantec Corp.’s FileStore N8300 is a scalable clustered NAS system built on Symantec Corp.’s Veritas Storage Foundation file system. FileStore supports up to 16 active-active 2U and 4U nodes, and 1.4 TB of total capacity. FileStore also has built-in Enterprise Vault and Clustered File software.
The Red Hat Storage Software Appliance (SSA) uses Gluster Inc.’s GlusterFS open-source clustered NAS software, which Red Hat acquired for $136 million in October 2011. The Gluster software appliance runs on commodity physical servers and as a virtual appliance. Red Hat has already added its Red Hat Enterprise Linux (RHEL) operating system to SSA, which supports synchronous and asynchronous file replication.