RAID Storage--Exploring All Channels

If maximizing RAID storage power and strengthening server support sound promising, surf the fibre channel— the next tech wave to boost the potential of RAID.

BY MARIE RANOIA ALONSO

Imagine that you're on a tight deadline to finish a four-color project—a high-end, 110-page catalog featuring automotive accessories for a popular sports utility vehicle dealer. It is 8 p.m. on Tuesday. All is going well. Images have been scanned and the project is almost done being pushed through the prepress department.

Working late and feeling benevolent, you decide to order pizza for your night shift, kick back, send a few long overdue e-mail responses to colleagues and review some monthly bookkeeping, as well as scan through resumes in your search to hire another salesperson.

Life is good.

But, suddenly, your server goes down. Your prepress manager can't access the information located on that server to finish the automotive accessories catalog. The job is due Thursday morning, bright and early. And the client doesn't have a sense of humor.

You quickly forget about pizza. Unless, of course, you have implemented a Storage Area Network (SAN). This new solution is similar to a local area network (LAN), only it is ideal for connecting storage devices to multiple PCs and servers.

Why a SAN? With a SAN in place, the end result for the above scenario is a more connected environment, which provides users with multiple paths to their digital data. At the same time, a SAN shields the rest of the network from large files that would bog down a LAN's backbone. In other words, by creating a SAN, the company increases its LAN speed and increases the reliability of its operation.

SANs are dedicated networks consisting of servers; external storage devices; server-based fibre-channel adapters (NICs); appropriate fibre-channel network devices, such as hubs and switches; and network and storage management tools, including—and especially—RAID. A storage area network consists of all of these pieces brought together.

At present, there are a series of technical initiatives that point to the eventual, vast adoption of fibre channel as perhaps the prime networking technology for RAID storage in a SAN environment.

Fibre channel-based SANs offer many benefits over current storage configurations—which traditionally involve SCSI cables—connecting devices to a single bus. SAN benefits include:

• A high-bandwidth infrastructure designed to scale upwards with increasing I/O demands; a single, full duplex, 1GB fibre channel link can achieve 200MB/sec. peak bandwidth;
• Reduced cost of ownership as increased automation of virtual storage pools allow dynamic reconfiguration of storage farms;
• Increased server CPU and LAN efficiency as storage-intensive processes, such as backup and recovery, are off-loaded to the SAN;
• Improved digital data availability through redundant paths to storage devices via multiple servers, enabling automated recovery during scheduled downtime or server failure;
• Enhanced scalability due to significantly increased addressing capabilities and better disaster tolerance with an ability to perform remote mirroring and off-site backup; and
• Independently expandable storage capacity and computing power in response to the ever-changing demands of the end user.

In short, SANs combine the LAN attributes of flexibility, scalability and manageability with the high bandwidth and rock-solid reliability of legacy storage I/O protocols.

RAID developer MicroNet has launched FibreFlex, a multi-platform compatible, fibre channel SAN solution that enables fast data throughput. At the heart of the solution is MicroNet's Genesis, a high-capacity RAID system with up to 1TB of storage optimized for the critical needs of prepress and video applications. Designed for prepress and commercial printing environments that work with exceptionally large digital files, FibreFlex provides all network users full access to centralized data while eliminating network bottlenecks.

In application, FibreFlex eliminates bandwidth issues by allowing multiple system users to simultaneously access the network's largest data or graphic files without creating network slowdown.

"FibreFlex is a fully functional and interoperable SAN that utilizes the full power of our RAID system, Genesis," reports Brian Lee, prepress business development manager at MicroNet. Based on MicroNet's DataDock technology, Genesis houses up to 28 hard-drive modules ranging in capacities from 9GB to 36GB each. Genesis is scalable, offering 63GB to 1TB of storage for a wide variety of needs.

MicroNet's Lee reports that a popular Genesis configuration integrates ATTO Technology's dual FibreBridge, allowing users to leverage current investments in legacy SCSI drive mechanisms, while achieving high-speed fibre channel connectivity.

As another alternative, RAID provider Ciprico offers two fibre channel disk arrays that are solid fits for SAN environments: the 7000 Series and FibreSTORE. The 7000 Series RAID array operates at full speed fibre channel and can be striped together for even higher speeds. Inside the 7000 are nine drives (9GB, 18GB or 36GB capacities in each drive) for up to 288GBs per disk array. In the event a drive fails, it can easily be hot-swapped, and there is no performance degradation. The failed drive data is regenerated on-the-fly. The 7000 also comes with hot-swap power supplies and cooling modules.

Ciprico's FibreSTORE is a JBOD disk array with the full speed performance of fibre channel. The FibreSTORE handles any combination of disk drives in a single enclosure, from a minimum of four drives in a single enclosure up to nine. Either 9GB or 18GB drives are supports for up to 144GBs per disk array. The FibreSTORE has built-in, daisy-chaining capabilities to provide an easy way to add more storage. It also has hot- swap drives, power supplies and fans.

"SAN technology holds great promise for productivity improvement in the printing industry," contends Susan Leenerman, director of marketing at Ciprico. "Its most important attribute is performance. Any workstation that has performance and productivity limitations due to low bandwidth or storage can be attached directly to a SAN."

Typically based on fibre channel, SANs deliver 100MB of storage bandwidth directly to workstations. With the increase of printing jobs being digitally moved around the shop, significant productivity improvements on a daily basis are critical. As fibre channel becomes increasingly affordable, Leenerman states, the cost to implement SAN will be minimal.

"Beyond performance, other SAN attributes will streamline the flow and management of data throughout a printing facility,"she continues. "Central management of the storage reduces risk and improves efficiency. Scalability allows sites to build their storage infrastructure based on need—not on predefined vendor configurations."

Ontario-based Legacy Storage Systems recently announced the UDSS-2 Fiber/LVD DiskARRAY, its latest addition to the UDSS DiskARRAY product line. The modular UDSS system features multiple LVD and fiber channel host connections, a new high-performance LVD internal bus and virtually unlimited, scalable storage capacity.

Adding to the original UDSS (Universal Data Storage System) concept of complete scalability, the UDSS-2 Fiber/LVD DiskARRAY incorporates multi-channel Low Voltage Differential. As many as seven internal bus channels, each capable of 80MB/sec. transfer rates, will connect from six to 30 hot-fix 9GB, 18GB or 36GB LVD drive modules. Capacities of up to 1,020GB per chassis can be linked together to achieve unlimited (multi-terabyte) capacities. Performance levels will far exceed that of systems with fiber connections to the disk.

"This new system is designed to address enterprise network storage requirements with high availability, without sacrificing performance," reports John Whyte, president and CEO of Legacy. "The UDSS-2 Fiber/LVD is both operating system and host-interface independent, allowing users the flexibility required through transitional architecture phases."

For the printing industry, the UDSS-2 Fiber/LVD DiskARRAY is designed to provide graphics system planners with strategic flexibility to grow capacity as production volumes increase. Its fiber channel connectivity will enable a range of collaborative creative and output functions through high-speed data sharing within and among workgroups in prepress environments.

On the other side of the fibre channel coin, Publishing Solutions, a subsidiary of Multigraphics, has been installing fibre channel-based storage solutions into the prepress market for two years. The company offers a third-generation fibre channel controller manufactured by LSI Logic called the 4766FC controller.

This solution provides fast implementation of fibre channel by connecting the server to the storage medium. At present, Publishing Solutions also offers gigabit ethernet technology, in the form of Packet Engines' G-NIC II, a gigabit ethernet PCI card for the Apple Macintosh that increases transfer efficiency of large files in multi-platform client/server networks by up to 4,000 percent.

"It is our view that gigabit ethernet in front of the server is clearly the solution of choice, whereas on the back end of the server, it is equally clear that fibre channel is rapidly displacing SCSI," contends Ray Leach, president of Publishing Solutions.

"With both technologies—gigabit ethernet and fibre channel—a new paradigm has been created," Leach adds. "The data packets are delivered to and from the server in excess of the server's ability to process the packets internally. With gigabit ethernet and fibre channel technology, today's networks and storage interconnects no longer are the bottlenecks of a prepress workflow—that goes to the server."

Is it worth investing in a SAN? Is fibre channel the direction of choice for your RAID tanks? Does fibre channel afford your prepress operation some flexibility—in times of (gulp!) server failure? Well, which scenario sounds better: attacking a crashed server in desperation or ordering a dozen pizzas?

A Heidelberg Briefing:
The Foundation and Merits of Fibre Channel

Editor's Note: Danny Kita manages the Operations Analysis Group, which is the consulting arm of Heidelberg USA. He is active in Printing Enterprise server and database projects. Recently, Kita shared his perceptions and forecasts on fibre channel technologies with Printing Impressions.

Fibre channel is an ANSI standard, approved in 1994, that's beginning to find its way into high-end storage products—especially those employing hardware RAID, as a replacement for the SCSI interface. It is important to note that SCSI is not going away. Heidelberg is finding that fibre channel presents a more appropriate technology for the higher end of the storage market and its demands.

Fibre channel's benefit lies in the fact that it is both an interface, like SCSI, and a network, like ethernet. It supports both SCSI and IP command sets, giving it the capabilities of both. In the evolution of printing and publishing, we have gone from sneakernet to a single production server, to the advent of multiple function-specific servers—one (or more) for production, one for a database.

This group of servers can benefit by having a directly accessible, aggregate storage area vs. having to reach through one of the servers to get to data. Fibre channel will be an enabler in the deployment of server clusters.

Fibre channel is the harbinger of intelligent storage peripherals that sit directly on the network (i.e., no server required as a traffic cop). These Storage Area Networks, or SANs, provide access to the storage directly. This dramatically changes the storage access paradigm and the way we think about workflow.

Thinking beyond print . . .
In the future, a storage solution may not only have to deliver high-resolution pages to support production, imposition and imaging for print, but may also have to stream a video clip to another customer over the Internet. Maintaining the video without choppiness—and, at the same time, supporting all production activities—is the requirement. Such scenarios can stress a SCSI interface to a large aggregate store. Fibre channel has the potential to deliver the goods.

Food for thought: A noteworthy aside is that the Gigabit Ethernet Task Force utilized some of the fibre channel standards for encoding/decoding, in order to shorten the standards process and get product to market. Fibre channel has been around for awhile. We are only now beginning to find application for it in the printing industry.

Squeeze More Storage Out of Your RAID

Editor's Note: The technical information below was provided by Michael Reiher, general manager, LizardTech.

As the use of digital files continues to proliferate in the graphic arts industry, keeping enough on-line storage available for massive images is always a challenge for today's network administrator. It's important to balance on-line storage with near-line or off-line storage in order to provide the best production performance and maintain a cost-effective storage strategy.

For on-line storage that needs to be accessed quickly or often, one strategy is to continually upgrade your RAID server with more capacity as your needs grow. The problem with this approach is this can be expensive given that good RAID systems range from $100 to $150 per gigabyte. Another approach is to try and squeeze more space from existing storage using a variety of file and image compression utilities and technologies. The most widely used compression technologies today include LZW and JPEG for grayscale and color continuous-tone images, and TIFF Group 4 for one bit image data and applications like StuffIt Deluxe for application files. What's attractive about these technologies is that they offer a lossless form of compression that allows images and documents to be recalled to their original state. LZW and JPEG image compression technologies are supported by many applications, print servers and RIPs, so using these file formats can be seamless to the users.

In order to achieve lossless or visually lossless quality for publication quality images the aforementioned technologies are only capable of 2:1 compression at best. This provides only a 50-percent increase in image- storage capacity, limiting the benefit of compression. Although options may be limited today, there are new alternatives quickly coming to the forefront that will help extend the benefits of compression—especially for large color images.

The viable alternatives include fractal compression or wavelet encoding. Fractal technology can achieve lossless compression at ranges as high as 3:1 and visually lossless up to 10:1 ratios. This means a standard 20MB image will drop to about 7MBs in its lossless mode and less than 2MBs in a visually lossless mode.

For more information, visit the Website featured above at www.lizardtech.com.