Conventional wisdom has frequently pigeon-holed Nexsan as the ‘economy’ disk solution and relegated their systems to a secondary storage tier. The problem with conventional ‘wisdom’ is that reality often proves it wrong. While Nexsan’s arrays may start out as the secondary tier they often migrate their way into primary storage because they prove themselves more reliable than the arrays that originally occupied that top position. Nexsan’s goal with the E-Series is to be considered a tier-one storage platform from the outset and, of course, continue to be the choice for the secondary tier as well.

In this new line of high performance storage arrays, which also features a new front panel look, the E18 supports 18 SAS drives for up to 10.8TB of capacity. SATA drives are on the roadmap for release later this year bringing the total to 46.8TB in this 2U chassis. The larger E60 can support 60 SAS/SATA drives, providing up to 120TB in its 4U footprint and 240TB later this year. The E18 and E60 also support SSD drives in capacities from 64 to 400GB per drive form-factor package. Finally, the E60X 4U expansion chassis was released, supporting another 60 SAS/SATA or SSD drives giving the E-Series a maximum density of 120 drives in 8U of rack space.

The data center is changing, with server virtualization, desktop virtualization, demanding large scale applications and of course, everything is web front-ended. Focused on higher-performance applications than Nexsan’s SASBeast line, the E-Series features the horsepower, throughput and reliability needed in the data center today. These systems have dual active-active controllers, each with 4GB DRAM cache (2GB in E18), plus two 8Gb FC and two 1Gb iSCSI connections per controller. Each controller also has two RAID engines, with dedicated hardware for RAID6 processing to keep throughput from degrading as capacity scales. The cache is also battery backed and flash protected.

Nexsan has always been a leader in high capacity storage systems, but storage density is what reflects their innovative approach to array design. Simply packing more spindles into a 4U chassis is just the beginning. Maintaining reliability, efficiency and cost-effectiveness are where the design is really put to the test. Nexsan developed the SATABeast and SASBeast arrays several years ago, one of the first truly high capacity, high density disk arrays for the midrange market. The new E60, with up to 120TB in a 4U chassis (240 TB coming soon) continues this design leadership.

Reliability is perhaps the first priority for an enterprise storage array, which means the design must control heat, flex and vibration. While redundant components and no single points of failure are important, and included in the E-Series, real reliability starts by preventing failures. Nexsan was a pioneer of the drive shelf design which places disk drives in counter-rotating pairs, so that adjacent drives rotate in opposite directions. This reduces the torque, or rotational forces, put on disk drive shelves and the vibration those forces cause.

Nexsan also developed the Active Drawer Technology™ which splits the chassis into three drive enclosures (two on the E18), each independent of the others. The drawers can be opened while the unit is powered on and drives replaced without disrupting the array’s operation. Aside from facilitating drive maintenance, Active Drawer Technology allows the weight of these extremely dense disk arrays to be more evenly distributed, reducing mechanical flex of the chassis and electronics. Without this technology, the entire 60-drive chassis would have to be removed, or pulled out, causing serious potential problems of stress to the chassis, circuit boards and connections not to mention the number of people required to perform this task.

Heat in these densely packed enclosures must also be controlled. The obvious way is with effective air flow and the E-Series have dual high-performance fans for each drawer, the first pushing air into one end and the second pulling air out of the other end. These fans are dynamically controlled to adjust individual drive speeds according to drawer temperature. But heat prevention is just as important, and Nexsan’s controller design helps address this issue as it reduces power consumption.

Storage system efficiency drives cost effectiveness and Nexsan’s E-Series include features that reduce power consumption and operational costs. Power consumption is a leading component of storage operational costs, something Nexsan addresses with a proprietary MAID technology. Short for “Massive Array of Idle Disks”, early MAID systems simply shut down unused spindles. But Nexsan’s AutoMAID technology actually sets drive speeds at one of four levels - from fully spinning to stopped - based on usage patterns. The result is a reduction in power consumed of up to 87% compared to traditional disk arrays, and comparable reduction in heat generated. On the OPEX side, the E-Series’ density can reduce array data center footprint and its higher reliability design and Active Drawer Technology can keep administrative overhead to a minimum.

Nexsan has been building reliable and cost-effective disk array systems for eleven years; they have 27,000 units installed in 60 countries and 600 channel partners. The E-Series is designed with the flexibility of mixed drive types and FC/iSCSI connectivity, plus the no-single-point-of-failure resilience of that’s expected of enterprise arrays. But they also have the functionality to address the storage conditions prevalent in the midmarket today. These systems offer economical capacity that scales to keep up with data growth and the higher array densities needed to fit into smaller data centers. Nexsan arrays also offer the simplicity of operation to support the IT ‘generalists’ that typically run these midmarket IT departments, with 10-minute setup, browser-based monitoring and Microsoft management tools.

Storage Switzerland’s Take - Hardware Matters!

It seems that using off-the shelf hardware or specialty storage appliances that run on commodity servers have become the norm in the storage space. Many storage vendors have apparently abdicated their responsibility over the hardware and instead focused on the software features they assume will sell more systems. But hardware matters and leaving it up to the user to make sure the platform chosen is adequate to run an important application may be asking for trouble. Companies that understand the details of reliable array design and efficient controller architectures, and put this technology into their storage hardware, will produce solutions like the E-Series that let users sleep at night. Nexsan’s history and innovation, plus a focus on space, power and cost efficiency continue make the new E-Series products a compelling consideration.

Eric Slack, Senior Analyst

Briefing Report

Nexsan is a client of Storage Switzerland