Isilon is a scale out network-attached storage platform offered by EMC Corporation for high-volume storage, backup and archiving of unstructured data. It provides a cluster-based storage array based on industry standard hardware, and is scalable to 50 petabytes in a single filesystem using its FreeBSD-derived OneFS file system.
An Isilon clustered storage system is composed of three or more nodes. Each node is a self-contained, rack-mountable device that contains industry standard hardware, including disk drives, CPU, memory and network interfaces, and is integrated with proprietary operating system software called OneFS (based on FreeBSD), which unifies a cluster of nodes into a single shared resource. 
Current Isilon hardware platforms include the S-Series nodes, which support high-performance, process-intensive, high-transaction applications; the X-Series nodes, which support high-throughput and high-concurrency application needs; the NL-Series nearline storage nodes, which support archiving, disaster recovery and disk-to-disk backup needs; and the HD-Series nodes, which support large-scale, high-density deep archive storage needs, as well as disaster recovery and, when combined with other nodes, an enterprise data lake foundation. Isilon also offers A-Series Accelerator nodes, which scale cluster performance and data backup processes.
Isilon Systems was a computer hardware and software company founded in 2001 by Sujal Patel. It was headquartered in Seattle, Washington. It sold clustered file system hardware and software for digital content and other unstructured data to a variety of industries. Isilon Systems designed and developed its clustered storage systems specifically to address the needs of storing, managing and accessing digital content and other unstructured data.
Isilon Systems received $8.4 million in Series A venture funding in 2001, $15 million in Series B funding in 2002, and $20 million in funding in 2005. Investors in Isilon Systems have included Atlas Ventures, Focus Ventures, GCV Capital, Lehman Brothers, Madrona Venture Group and Sequoia Capital.
Isilon Systems became a publicly traded company on December 16, 2006. By this time, Isilon was selling its products indirectly through a channel partner program that included over 100 resellers and distributors, as well as directly through a field sales force. Its customers included NBC Universal, Cedars-Sinai, Kelman Technologies, and Kodak, among others.
Poor initial performance of the new public company led to management changes in 2007 that brought back founder Sujal Patel as CEO. In 2008, details emerged around an internal audit of Isilon System’s financials that led to a restatement of earnings. Just before the company would have announced four profitable quarters in a row – the first in profitable year in the company’s history – Isilon Systems was acquired by EMC Corporation in November 2010 for $2.25 billion.
EMC said that with its acquisition of Isilon, it would be better able to provide storage infrastructure for private and public cloud environments, with a focus on so-called big data, like gene sequencing, online streaming, and oil and natural gas seismic studies. At the time of acquisition, the list of Isilon’s clients had grown to include Sony, XM Radio, LexisNexis, Facebook, MySpace, Adobe, and several major movie studios and TV networks.
On November 10, 2015, EMC announced an expansion of its Isilon NAS portfolio with a scaled-down, software storage system for remote locations, a cloud migration application and high-availability upgrades for Isilon OneFS. The two software additions, IsilonSD Edge and CloudPools, will be available alongside the new version of OneFS in 2016. They are part of the vendor's data lakes strategy for storing and managing unstructured data in large repositories. The new offerings will, according to one analyst, deliver a data lake-ready platform to enterprises with high-speed data analytics, and are aimed at three aspects of the Data Lake, the edge, the core, and the cloud.
Technology and Architecture
Isilon clustered storage system architecture consists of independent nodes that are all integrated with the OneFS operating system software. The systems can be installed in standard data center environments and are accessible to users and applications running Windows, Unix/Linux and Mac operating systems using industry standard file sharing protocols over standard Gigabit or 10-Gigabit Ethernet. Nodes within the clustered storage system communicate with each other over a dedicated InfiniBand local area network. The architecture is designed so that each node has full visibility and write/read access to or from a single expandable file system.
The current Isilon product line consists of S210 performance-optimized primary storage nodes; X210 and X410 throughput performance/capacity nodes, NL400/NL410 nodes for nearline storage, high-density HD400 nodes and A100 accelerator nodes. Isilon clusters can hold a mix of the various node types. 
The most common types of nodes are the S-series nodes that deliver high IOPS, the X-series nodes which deliver high throughput, and the NL-series nodes which deliver high-capacity. All types of nodes can co-exist simultaneously in a single file system on the same cluster. The scale-out architecture can grow up to 144 nodes per cluster and nodes can be added as needed for capacity and/or performance. This allows files to be stored in one container and eliminates islands of storage (a common administrative pain point). Isilon also delivers relatively high storage utilization rates.
Performance Accelerator Nodes allow enterprises to easily scale performance to meet specific business needs without adding capacity. They include the EMC Isilon A100 Backup Accelerator, which supports leading network data management protocol (NDMP) data backup software products and multipathing, and the EMC Isilon A100 Performance Accelerator, designed to quickly increase processing power, memory, bandwidth, and parallel read/write access capabilities.
The core technology of the Isilon clustered storage consists of OneFS, which provides a single unified operating system and can deliver over 200 GB/s of aggregated throughput (depending on cluster size). The OneFS software is designed with file-striping functionality across each node in a cluster, a fully distributed lock manager, caching, fully distributed meta-data, and a remote block manager to maintain global coherency and synchronization across the cluster.
Data protection is formed using mathematical algorithms instead of using traditional RAID 5. When a file is written it is spread across all nodes using parity calculated by which level you set the whole or parts of the cluster to using a Reed Solomon error correction coding.
OneFS allows a storage system to grow symmetrically or independently as more space or processing power is required, up to 50 PB and 3.75 million file operations per second (FOPS). To further accelerate performance, Isilon products incorporate features including a scale-out flash tier providing over 700 TB of flash cache in a single cluster, as well as support for Microsoft SMB 3.0 Multi-Channel.
Isilon provides multi-protocol access to files using NFS or SMB/CIFS or FTP. In addition, Isilon supports HDFS as a protocol allowing Hadoop analytics to be performed on files resident on the storage. Data can be stored using one protocol and accessed using another protocol. The key building blocks for Isilon include the OneFS operating system, the NAS architecture, the scale-out data lakes, and other enterprise features.
Recent deals between EMC and Cloudera will allow the Cloudera Enterprise Hadoop kit to be sold directly from EMC and its channel partners. The deal is expected to benefit the thousands of EMC Isilon customers with existing data lakes by providing a base for running analytic processes on their data, giving them access to Impala, Cloudera's open source, massively parallel processing SQL query engine that runs on Hadoop.
Awards and Recognition
- EMC Isilon received the highest overall score among nine companies rated by Gartner in its January 2015 “Critical Capabilities for Scale-Out File System Storage” report. This report also called out Isilon’s scalable capacity, performance, easy-to-deploy clustered storage appliance approach and feature sets.
- EMC was described by Gartner in its 2014 Magic Quadrant for General-Purpose Disk Arrays as a leader in the disk storage market because its management team invests heavily in its vision; is quick to correct mistakes; and is aggressive.
- EMC Isilon was included in ComputerWeekly’s 2014 survey of the “big six” storage array makers’ scale-out NAS product ranges.
- A 2013 report developed by Forrester Consulting and commissioned by EMC conducted in-depth interviews with four existing customers and found that these companies achieved benefits including lowering upfront costs, reducing the need for administrative resources, reducing the need for training and professional services, and avoiding the cost of traditional storage media. It calculated at 167% return-on-investment with a payback period of less than 6 months.
- Enterprise Strategy Group called out EMC Isilon S200’s record-setting scale-out performance in 2011, citing the 1 million FOPS achievable then, as well for its modular architecture.
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