Magazine Article | November 1, 2001

NAS To SAN: 'I Love You, Man'

Source: Field Technologies Magazine

Storage vendors are working to close the interoperability gap between NAS (network attached storage) and SAN (storage area network). Industry insiders outline the benefits for customers who prepare now to meld these two natural playmates.

Integrated Solutions, November 2001

In looking back at their elementary school days, most people remember the emphasis on the "3Rs" - reading, writing, and 'rithmetic. After all, those "hard skills" have likely been emphasized repeatedly in their adult lives. But what people might not instantly recall is that they were also graded on another key ability, one defined by behavior rather than knowledge: "works well with others." The same criterion can be applied to storage solutions. When the report cards are issued, network attached storage (NAS) should receive an "A" in the "works well with others" category. As in grade school, a key indicator for this quality is the willingness to share, and sharing is a NAS device's fundamental purpose. After all, it happily shares the files it stores with multiple users on a network.

According to Zachary Shess, senior analyst, storage and storage management, for the Aberdeen Group (, "Network attached storage has traditionally been designed to do one thing - serve files. If your basic need is to serve up shared files on the LAN, network attached storage is inexpensive and not IT-intensive." Derek Gamradt, CTO for storage services provider StorNet, Inc. (Englewood, CO), agrees that NAS fulfills its file delivery role well. "If a customer is looking for file-based access, NAS consolidates the data, is easy to maintain, and can be shared by UNIX and NT users." Suggesting that convenient file delivery is as important as overall storage capacity, Mark Amelang, director of field and industry marketing for Auspex Systems, Inc. (Houston), said, "In the end, who cares how much data you can store if network users can't quickly get to the specific files they need? For companies needing ubiquitous file access, NAS is a key driver. Storing data in a central location rather than across multiple application servers makes it easier for administration, backup, and security."

NAS Applications Abound
Because NAS can give multiple network users access to the same files and can accommodate different operating systems, it is particularly valuable for collaborative projects, such as engineering and product development. "In oil and gas industries, for instance, geoscientists need to share seismic survey data," Amelang stated. "In software development, codes are being checked in and out by various developers. During a software build, when all the codes that have been written in the course of the day are turned into programs, file sharing enables fast turnaround, reducing the company's time to market."

Dick Vanek, president and CEO of Excel/Meridian Data, Inc., offers the reminder that NAS devices can store and serve large files - in the multiple GB range, for example. "The ability to handle large files makes NAS valuable for image-heavy applications, such as CAD (computer-aided design) and CAM (computer-aided manufacturing)," Vanek said. Vanek also recommends using NAS devices for storing and providing access to photographs used as a more quickly delivered and less costly substitute for streaming video. "Day care facilities, for example, are beginning to install cameras that take snapshots of the various rooms and activities at timed intervals - perhaps every minute or two. By accessing the photos, parents have the opportunity to check in and see how their children are doing. Of course, that service generates a lot of large photo files to be made accessible," Vanek said.

NAS Ready To Partner
Beyond its primary file-sharing function, NAS is moving toward working well with another "other" - SAN (storage area network). Although often presented as competing storage solutions, NAS and SAN actually are moving toward true interoperability. Consequently, customers may want to allow these compatible storage infrastructure components to play together, particularly since they perform differing data storage and access needs. "People are beginning to understand that NAS and SAN architectures have complementary uses," Shess said. "SAN architecture facilitates high speed block I/O (input/output) transfers, while NAS allows for file sharing over the LAN. A large customer may need both. So you're starting to see vendors of all sizes creating devices that can support both SAN and NAS functionality."

Amelang also notes that NAS' ability to get individual files to users and SAN's ability to move block data and do LAN-free backup make the two storage topologies natural partners. As he points out, vendors are already developing products that are designed to allow a NAS front end, or "head" device, to function as a conduit to a SAN. However, Amelang believes that, for such devices to work with any SAN infrastructure, one key change is required. "Right now, there are no industry standards for SAN," Amelang said. "When there are standards, customers will be able to hook their NAS head into any company's SAN technology and devices."

Vanek agrees that interoperability hurdles remain but senses they are fast becoming insignificant. "NAS and SAN are coming together whether people want them to or not," Vanek said. "At some point the ability to run iSCSI (Internet small computer system interface), Infiniband, and FibreChannel over NAS devices will make the NAS design very similar to SAN." According to Gamradt, vendors are already offering dual-purpose topologies in the same unit. "Some products can serve up storage pools defined as either block-level SAN or file-level NAS. An enterprise RAID (redundant array of independent disks) solution, for example, could be configured with one half attached to a SAN and the other half operating as a standard NAS device."

As vendors work to bring NAS and SAN closer together, a crucial issue, according to Shess, is the degree to which data will be transferable. "One theory is that companies will be able to send their data to any type of device and access any type of data from any device. However, making everyone's data work with yours - using different file protocols, over different operating systems - is not going to happen right away," Shess said. "There's another possibility that, ultimately, companies will work to align only their data and their business partners' data."

While it is too early to predict exactly how the melding of SAN and NAS will evolve, all of the industry insiders suggest that the ultimate goal of seamless interoperability and data sharing can and will be reached. Their confidence should embolden customers who need to build or upgrade their storage infrastructure soon.

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