ISE - THE NEW FOUNDATION OF
DATA STORAGE

ISE: Intelligent Storage Element Technology

For the last several decades the underlying elements of data storage—disk drives, drive enclosures, and controllers—have remained more or less the same, and have been unable to keep pace with dramatically changing business requirements. Xiotech offers a fresh approach with its Intelligent Storage Element technology - a storage foundation that sets new standards for reliability, performance, scalability, and value.

This year the channel-attached disk drive turns 56 years old (IBM RAMAC in 1954), and the internal, bus-attached disk drive turns 37 years old (Winchester 30/30 in 1973). RAID had its beginnings 30 years ago (Norman Ken Ouchi of IBM was awarded a patent for what would later be termed RAID 5 by Patterson, Gibson, and Katz in 1988), and the SCSI interface celebrates its 24th year (published as an industry standard by ANSI in 1986). This turns out to be a very long run for what are still the fundamental foundations of today's storage systems.

CorteX Developer Community

CorteX is a RESTful API that allows ISE to be easily integrated into software as an application resource to control or automate storage management.  This capability and control over storage elements is a powerful value-add to data centers and one of the three components of an Intelligent Application Storage architecture.

Learn More »

Since the advent of the Small Computer System Interface (SCSI) and the realization of a Redundant Array of Inexpensive Disks (RAID), data center disk storage has matured to its present form that we know as modular or monolithic disk arrays. These arrays are available with various interconnected protocols and in various capacity points and performance levels. However, the essential elements of data center storage (disk drives, drive enclosures, and controllers) have changed little over the years. In relation to this foundation, neither IT operations nor fundamental element characteristics have changed significantly.

We still perform SCSI I/O to a set of disks fastened in an unintelligent enclosure. We still rebuild disks when they are flagged as failed. We perform RAID as a one-dimensional stripe of data over a given set of disks. In addition, the fields of architecture and physics teach us that a structure is only as strong as its foundation. This principle, when applied to modern disk arrays, means that we cannot progress much further (outside of capacity increases) unless we completely redesign the foundation to become much faster, more reliable, and more intelligent than it is today. Only in this manner can we progress beyond the decades-old disk storage paradigms in place.

Three Issues with the Current Foundation

1. Fixing What Isn't Broken

The structure of the current foundation forces IT staff and vendor service staff alike to fix what isn't broken—namely, disk drives. According to Seagate Technology, the world's leading provider of disk drives, nearly 75 percent of drives returned to it as "failed" are examined and found to be without failure, a finding commonly called "no trouble found." Of course, one would think that modern array controllers could discriminate between transient failure and true failure—but because of the nature of SCSI I/O and RAID, they cannot. This forces a "service event"—i.e., several layers of error-prone manual intervention, coupled with significant time and money—to occur. Ironically, this service event is completely unnecessary nearly three-fourths of the time. In terms of both business interruption and financial impact, clearly, the unnecessary service event is a significant issue.

2. Disks Are Too Large... And Too Small

Current disk drives are too large and too small—at the same time. Drives that are too large—e.g., a capacity of 1 terabyte on a single drive—require inordinate amounts of time to rebuild given a failure declaration by an array controller. Testimonials abound on the fact that it may require tens of hours to rebuild a 1 terabyte drive via well-known RAID techniques. In addition, the prospect of reading 4 or more terabytes just to rebuild 1 terabyte (e.g., in a 5-drive RAID 5 set) begins to push the physical limits of disk drives' ability to read without error, a metric known as unrecoverable read error rate (UER). For example, it is well known that a rebuild of a 1 terabyte drive in a 5-drive RAID 5 set with a drive UER of 1 in 100 trillion (1014) bits will fail 40 percent of the time. A drive that does not rebuild means a potential catastrophic array failure.

At the same time, drives that are too small—e.g., a capacity of 73 gigabytes on a single drive—require dozens or even hundreds of disks to reach performance points necessary for today's transactional applications and other high I/O per second (IOPS)/quick response time (RT) workloads. Even though adequate performance levels may be reached, the prospect of a farm of hundreds of these small drives, forcing a very small mean time between service events (MTBSE) is becoming a poor business proposition. The mean time between failure (MTBF) mathematics is inescapable in today's drives-in- unintelligent-enclosure designs. The more drives you spin, the more failures you will see over time.

3. Storage Controllers Are Becoming Bottlenecks

Current storage controllers are quickly becoming bottlenecks to application processing due to the inherent nature of their design. They must perform RAID; manage a static cache; and attempt to manage processes such as drive sparing, drive rebuild, parity placement, diagnostics, Fibre Channel Arbitrated Loop (FC-AL) protocol handling and repair, and so on.

Truth be told, there are myriad complex calculations and built-in assumptions in the storage controllers of today. This leaves little headroom for intelligence that would actually enhance the value of disk storage to modern business organizations. In short, storage controllers have an ever-impossible job to perform—trying to "herd cats," i.e., hundreds to thousands of disk drives that can and do fail in a plethora of ways, expected and unexpected. Given these fundamental and progress-inhibiting issues with the foundation of disk storage arrays, what can be done to resolve them? Can the decades-old principles of array design be kept in place for more decades without serious redesign? The answer, in short, is no.

ISE: The New Foundation of Data Storage

To overcome these issues, in 2007, Xiotech acquired the Advanced Storage Architecture (ASA) group from Seagate Technology. This group of talented engineers and designers was informally known as the "Skunk Works" in respect to the legendary design group at Lockheed Martin. Like the original Skunk Works, the ASA group designed and built a revolutionary technology—the Intelligent Storage Element (ISE™).

ISE incorporates innovative and disruptive thinking around the foundation of storage—the disk drive and its enclosure. With its game-changing design, ISE delivers reliability, performance, and scalability that no other storage system today can match. ISE is an integrated environment of:

  • Single or dual sealed DataPacs, each with up to 8 terabytes of capacity—up to 16 terabytes in just 3U of rack space
  • Dual Managed Reliability Controllers, which locally manage cache, data recording processes, and more
  • Dual power and cooling units
  • Dual battery modules

Unprecedented Reliability

ISE reaches reliability levels impossible for standard drives and enclosures, providing more than 100 times the reliability of a regular disk drive enclosed in a typical storage drive bay—significantly reducing service events and their impact on IT organizations.

Because of such reliability, Xiotech provides an industry-exclusive five-year hardware warranty with all its ISE-based Emprise™ systems. This can save organizations thousands of dollars over typical systems that offer only one- to three-year warranties followed by hefty maintenance renewal charges.

How is such reliability achievable?

Significantly improved environmentals ISE dramatically reduces heat and vibration—the two greatest causes of drive failure.

ANSI T10-DIF ISE is one of the first storage technologies to incorporate ANSI T10-DIF for end-to-end error correction and detection and the prevention of silent data errors. ANSI T10-DIF provides:

  • Logical block guard for comparing the actual data written to disk.
  • Logical block application tag to ensure writing to the correct logical unit.
  • Logical block reference tag to ensure writing to the correct virtual block.

Self-healing technology ISE automatically performs preventive and remedial repair of components within its sealed DataPacs—requiring no intervention to pull failed drives. When ISE detects a potential drive error, it:

  • Migrates data from the suspect drive to another drive within the DataPac
  • Resets and/or power cycles the drive
  • Performs a complete factory remanufacturing process
  • Recalibrates heads
  • Rewrites servo tracks
  • Performs a low-level format

The result is the equivalent of a fresh, factory-remanufactured drive. Only the components that are irreparable are taken out of service. All others are restored to full activity.

Granular recovery ISE can recover data down to a level of granularity impossible with traditional RAID controllers that can only "see" an entire drive.

Self-Sparing Each sealed array includes spare capacity, which overcomes the need for service if there is a failure within the DataPac.

Industry-Leading Performance and Efficiency

Over the decades, storage systems have evolved such that the three key components—drives, drive enclosures, and system controllers—are typically manufactured separately and independently. Each component has a significant "compatibility burden," where it must interoperate across multiple manufacturers and multiple generations of other system components.

This results in significant processing overhead to achieve compatibility, an accumulation of "Band-Aid" fixes as components evolve, and inherent inefficiencies that significantly affect system performance.

Additionally, most systems are designed with centralized, controller-based intelligence that must manage:

  • High-level storage processing: Virtualization, FC-AL protocol handling, host connectivity, overall system management.
  • Drive management: RAID and cache management, drive rebuilds, drive sparing.

As systems grow, the compatibility burden and centralized management limit overall performance and reduce the intelligence available for higher-level storage functionality. ISE overcomes these issues by tightly integrating the drive, enclosure, and controller software and firmware, and by distributing much of the processing and cache into the enclosure.

ISE software also incorporates technologies to reduce processing complexity and provide more robust functionality with no loss in reliability:

  • Improved data organization for high-speed rebuilds, maintenance operations, and replication (45 percent faster rebuilds than any known array).
  • Optimal actuator profiles for each DataPac.
  • More efficient striping.
  • Less qualifying for bug-free interaction between controllers and groups of disks.

ISE not only delivers impressive performance, but delivers it at a lower cost. The Storage Performance Council (SPC) validated that ISE (Emprise 5000) provided one of the industry's lowest costs for both I/Os per second (IOPS) and megabytes per second (MBps).1

Ultimately, this means that organizations can achieve the performance they require with less disk—significantly lowering costs.

In addition, unlike most other storage offerings, ISE performance does not degrade as capacity utilization increases. With other systems, organizations often are forced to buy additional capacity (disk drives) simply to meet performance demands. This requirement and expense are eliminated with ISE.

1. Best protected disk array price/performance for SPC-1 IOPS; industry-leading price/performance for SPC-2 MBps—composite mirroring and large file mirroring—as of May 12, 2008. Audited reports are available at: www.storageperformance.org/results/benchmark_results_spc1#a00064 and www.storageperformance.org/results/benchmark_results_spc2#b00031.

Maximum Scalability

Supporting performance-starved applications, consolidating infrastructure, simplifying administration and creating a greener data center require highly scalable storage solutions capable of meeting a variety of enterprise deployment requirements: NAS, SAN, DAS, and storage as part of your application service.

ISE storage blades contain their own storage engines, effectively eliminating the I/O bottlenecks created by traditional NAS, SAN, and DAS storage arrays that have to manage RAID, cache, low-level disk processes, file services and other overhead activities. As capacity grows, so does the performance of ISE-based storage solutions. Each ISE storage blade added brings more processing power, increasing overall storage I/O performance in a linear fashion.

Each Xiotech ISE-based storage solution leverages ISE storage blades, giving you the flexibility to acquire, implement, manage and scale the use of your storage resources anywhere, anytime within a single ISE management platform.

Emprise 5000

This ISE-based storage solution can be used for mixed or dedicated workloads and intelligently integrated into a variety of direct-attached or switch-attached infrastructures.

Emprise 7000

This ISE-based mid-range storage solution combines ISE storage blade capabilities with Xiotech's proven virtualized distributed cluster architecture, eliminating the sub-par performance and scalability of traditional network storage solutions.

Emprise 9000

This ISE-based, scale-out, enterprise storage solution fully leverages ISE storage blades' intelligence, performance, reliability and scalability to meet the most demanding application-specific or mixed workloads.

ISE NAS

ISE NAS combines Symantec's FileStore software engine with ISE Storage Blades, creating near-linear performance, scale-out, file storage services capable of handing a variety of file-level workloads.

A Platform for the Future

Computing has changed significantly in the last 20 to 30 years. Adherence to Moore's Law has led to exponential growth in processing power, network throughput, and storage densities. Business practices have driven an ever-increasing demand for storage in terms of capacity, availability, and protection. At the core of it all are the decades-old disk drive, RAID, and SCSI technologies, all wrapped in an accumulated protective layer of complex and expensive fixes to make up for their shortcomings.

ISE is a fresh new approach to the fundamental aspects of storage, setting new standards for reliability, performance, and scalability. Rather than shoring up the foundation that has been with us for decades, ISE is the new foundation that promises to fulfill storage needs well into the future.