The PCIe solution from ExaSAN An outlook on how PCIe can help with your media and entertainment video environment. Who we are? Since 1995 Accusys Storage Ltd. has created generations of cutting-edge and innovative storage products that have helped customers around the globe store, protect, and manage their most important media assets. The Accusys RAID Kernal has deployed over one million copies with overwhelming testimonials for its compatibility and stability. Our customers use Accusys storage solutions to create and distribute their most celebrated videos, music, and award winning films. To date, Accusys has been constantly improving and perfecting its function with essential services required by Windows, Mac, and Linux operating systems, SAN software, and media applications. From PATA RAID to the latest ExaSAN PCIe product family, we continually invest and develop high speed, stable, and economical storage solutions that focus on high-end video and audio production applications. Advantages of PCIe Speed ExaSAN has leveraged a native external PCI Express (PCIe) protocol and focused in developing external PCIe storage systems, which is greatly different from traditional FC & iscsi storage. The ExaSAN family takes advantage of the extremely high speed PCIe protocol and has successfully developed the PCIe SAN architecture, providing all the necessary components required for the video and audio production DAS and SAN storage environment, while ensuring cost-effective, easy to use storage systems compared to traditional storage. What is the ExaSAN Solution? ExaSAN is a family of storage, switch, and host bus adapter products that take advantage of well-known PCIe (PCI Express) technology speeds, standards, and roadmap. The current ExaSAN products employ PCIe 3.0 protocol that provides 8 Gb/sec per lane transfer rate. With 4 lane QSFP (Quad SFP) connectors and copper/fiber cables, ExaSAN can transfer up to 32 Gb/sec using single port QSFP HBA s. With a dual port QSFP HBA, ExaSAN RAID storage data transfer rates up to 5000 MB/s to the connected workstation. The ExaSAN total solution, including its complete line of rack mount and tower systems, PCIe switch systems and accessories, puts the benefits of shared, scalable, and high-performance storage within easy reach of organizations with limited IT resources and budgets.
The Media and Entertainment Video Environment Post production work including non-linear editing (NLE) requires high bandwidth storage and guaranteed sustained throughput to eliminate dropped frames and to quickly move multiple 2K and 4K video streams being processed, and ExaSAN storage systems meet those demands. The ExaSAN high bandwidth technology speeds up workflow editing projects saving the client time and money. Whether it s collaborative video editing in a post-production workgroup, or a shared research project in a university, the ExaSAN solution offers a range of performance levels and storage capacities that scale to meet the needs of small-to-medium-sized organizations. Equally important and useful is its integrated design, suite of built-in management tools, and centralized administration and monitoring, which eliminate the need for a staff of experts to install and maintain a SAN for the workgroups.
Performance Optimization Accusys has developed several unique performance optimization features for the demanding video post-production editing studio where storage speed, video stability, and keeping the workflow running smoothly are critical needs. This means high speed access to video files must be maintained and video frames should be uninterrupted (no dropped frames). What are frame drops? If the system performance is impeded or disk is not fast enough, frames may be dropped during the capture process meaning one or more individual frames are not captured at all. When a frame is dropped during capture, the frame before it is repeated. As a result, a frame you see while editing may not be the frame you see when the film is cut. Obviously, this can cause significant delays in completing projects. Accusys Performance Equalization Mode, Disk Lag Proof, and RAID Slicing features keep the video editing process running smoothly without having to recapture video. Whatever the transmission method, the data transmission process cannot be guaranteed at the same speed at all times. In other words, despite inconsistent flow rate, water in the pipeline would eventually reach the output. But when we are facing this in certain applications, such as video streaming that requires very smooth and sustained throughput performance, frame drop will occur. Overcoming frame drop in high bandwidth video applications is a significant task; using a performance range with the lowest peaks in a fluctuated bandwidth, which means 20% loss of average disk bandwidth. Performance Equalization Mode Performance Equalization Mode (PEM) is designed to eliminate frame drop and ensure smooth and stable performance. The user can select and activate this feature via ExaSAN RAIDGuard X GUI storage management software. This unique access command will adapt the RAID controller memory caching management behavior and will make continuous I/Os more smooth and dramatically reduce the large fluctuations effectively during data transmission. This ensures that ExaSAN is able regain the 20% loss in bandwidth and provide stable high throughput and prevent frame drops.
Disk Lag Proof ExaSAN uses RAID technology in order to increase disk performance and data protection; generally users configure ExaSAN RAID using RAID 5 (single hard disk tolerant) and RAID 6 (two hard disk tolerant). When users are having problems with one hard disk in a RAID set; the hard disk is still accessible but because of age or bad sectors the RAID set bandwidth performance can decrease because of the faulty hard disk slow response behavior or even drop abruptly. This situation in video applications will cause frame drops and could cause the user extra time to recapture the video. To deal with such an issue, ExaSAN offers Disk Lag Proof (DLP). When one hard disk in the RAID 5 or 6 set is slow in responding, DLP will perform a fast data regeneration using the correct data and parity from the remaining hard disk in the RAID set. While the regeneration is occurring the host system will be receiving correct data and normal response time from the RAID set. The user will continue to edit video without frame drops during the degradation mode. What type of media content is being created and where to store it on a hard disk drive (HDD) or RAID system is important to improving the overall speed of the device. Another factor to understand is that the storage device data transfer rate is fastest when it is empty, as they get closer to being full the data transfer rate decreases. To help understand this a basic knowledge of hard disk drive technology is important. Today s HDDs use Zone Bit Recording (ZBR) to write sectors on an HDD. ZBR is used by an HDD to store more sectors per track on outer tracks than on inner tracks. This being the case, the data on the outer tracks will have the highest data transfer rate. This is why testing an HDD or RAID when they are new or empty, or after defragmenting will often show their highest data transfer rates. After some time, when more data are stored in the inner tracks, the average data transfer rate will drop because the transfer rate in the inner zones is slower. RAID Slicing ExaSAN RAID slicing overcomes the inherent design of how data is stored on an HDD or RAID system by subdividing a RAID array into segments, or slices. These slices are effective hardware partitions of all drives in the array. Each slice is a separate LUN and appears as a separate volume on the host computer. After slicing, the LUN map must be set for each slice.
RAID slicing is very beneficial in A/V applications where sustained transfer rates are important and vary depending whether they are 2k, 4K video or audio files. In Conclusion Accusys ExaSAN DAS and SAN storage systems have been designed specifically to address the critical needs of small and medium media organizations and independent professionals that require high transfer rates, stable video transmission, and considerable value. ExaSAN solutions are used in broadcasting, post-production, high-definition image processing, and other high bandwidth applications. ExaSAN storage is simple to install, and easier to use compared to traditional storage interfaces and configurations.