Consolidating NAS pays off

The role of network-attached storage may be changing as more and more storage managers discover the the benefits of using NAS to consolidate file servers.

Army Reserve consolidates its storage
The U.S. Army Reserve's 108th Division consists of 3,300 soldiers dispersed over 200,000 square miles in four states and Puerto Rico, with units located in 23 cities and towns. The primary mission of the Division is to provide training. Until recently, it relied on 23 servers running Windows NT at 23 separate locations. Not surprisingly, the management of systems administration was a nightmare. Even tasks as straightforward as backup and disaster recovery were nearly impossible, says William Bailey, network manager, Ciber Inc., a consulting firm hired by the Army to develop and support the Division's network operation.

With only five system managers available to cover this sprawling set of systems, the Division decided to upgrade its servers to consolidate and centralize storage. The plan called for moving storage from the 23 distributed servers to eight data centers. This would allow for efficient storage administration and effective file backup and recovery. "We wanted to be able to back up the data at each data center, and after the first master replication, we would just back up what has changed," says Bailey.

The solution called for the installation of Inline Corp.'s FileStorm network-attached storage (NAS) appliances running Microsoft's Windows Storage Server 2003 in each data center. "We were already a Microsoft shop, so this was a very easy way to go," Bailey says. Each site has a 360GB hot-swappable disk capacity. When completely installed, the system will provide 2.9TB of storage overall (360GB at each of eight data centers). The system came loaded with capabilities, including volume shadow copy services, distributed file services, file replication features, a Web-based user interface, Terminal Services support, resource management and antivirus software.

Initially, the NAS appliances were installed at three of the data centers. Immediately, administrators began using the advanced features for quick file recovery. "We make a lot of use of shadow copy across RAID partitions," says Bailey. Using a variety of high-speed links, users can get to any file at any data center. Although the Division isn't yet replicating data between data centers, it expects to in the future. It also expects to add support for Active Directory.

Based on preliminary results from the continuing implementation, the new NAS-based system is a winner. Server upgrades that used to take five days now take half that time because of centralized file servers and snapshot copies. According to Bailey, the reduced labor has already resulted in about $70,000 in savings over the first six months. Chalk up a victory for the Army.

The U.S. Army Reserve's 108th Division faced a massive consolidation challenge, moving the workload of 23 Windows servers at 23 locations to eight data centers. It might have built an elaborate storage area network (SAN) to hold its 2.9TB of files. Instead, it opted for a set of network-attached storage (NAS) appliances running Microsoft Corp.'s latest storage operating system, Windows Storage Server 2003. "NAS seemed like the easiest way to go and it was also low cost," says William Bailey, network manager for Ciber Inc., Greenwood Village, CO, the consulting firm that consolidated the systems for the 108th Division (see "Army Reserve consolidates its storage").

A select group of storage managers like Bailey are bucking the trend toward "everything on the SAN" and are finding a place for NAS in the enterprise storage infrastructure. While NAS may ultimately be more limited than a SAN, these storage managers are leveraging its well-known ease of use in combination with increased capacity and new features to drive significant consolidation projects. And with more options to converge block and file storage, storage managers now can consolidate file storage with an eye toward a unified infrastructure later.

Stephen Foskett, practice manager for storage strategy at GlassHouse Technologies Inc., Framingham, MA, says the main payoff isn't where you might think it would be--replacing multiple smaller NAS devices with fewer large NAS devices.

"There aren't big savings from replacing six old NAS boxes with two newer, bigger ones. What you are getting is more reliable storage and greater storage density, which will reduce the footprint," he says. You also gain some licensing advantages and simplify the management, although management of NAS devices hasn't to date been a large issue.

Server consolidation, however, is a different story. Here, NAS can play a significant role in eliminating the plethora of servers that sprouted in companies in the '90s when direct-attached storage (DAS) was the main game and IT departments bought new application servers each time an existing one ran out of storage. Not only can you reduce the burden of managing an out-of-control server environment, but you can leverage the host of new features that have made their way into better NAS boxes. Those advanced features include replication clustering and SMI-S management (see "NAS management on the move").

NAS management on the move
The key to making network-attached storage (NAS) a major component in enterprise storage is storage management. "When SRM [storage resource management] products start reporting on NAS, IT will finally be able to control it," says Randy Kerns, senior partner at the Evaluator Group, Greenwood Village, CO. Although a few NAS vendors, such as Network Appliance Inc. (NetApp), have long provided storage resource management capabilities for its own products--and even exposed their APIs for use by others--multivendor NAS management has not been practical.

But NAS management is quickly changing. "The current version of SMI-S specifies information for NAS reporting," says Kerns. Most vendors have some form of SMI-S NAS reporting or will have it soon, he adds. Once NAS can be managed alongside SAN using the same tools, it will quickly assume a larger position in the enterprise storage environment.

Where NAS hasn't gained traction, at least not yet, "is for massive storage consolidation or to consolidate [block-level] enterprise application storage," says Foskett. Application consolidation remains the province of SANs. "A few companies I know are using NAS for database access, but they are just mounting it via NFS or Windows over CIFS [the Common Internet File System]," says Foskett. "It's a little like hammering a nail with a screwdriver. They do it because they can have many clients accessing the same data. They like the NAS interface, and performance isn't critical to them."

Server consolidation
Consolidation lowers costs by enabling centralized management. Chicago's Field Museum is typical: "We had multiple small servers with about 1TB of storage. It was unmanageable. So, we consolidated seven file servers on one NAS box," says Neil Young, manager of the museum's application and enterprise services group. Even large servers get maxed out and can't expand further, "but with NAS, we can just keep expanding as needed," he adds.

Except for the low end, NAS devices can consolidate many servers. "The filers can handle a lot if they are not swamped by client requests," Foskett explains. The limiting factor isn't the number of consolidated servers, but the volume of user traffic. Other storage managers report finding 10:1 file server consolidation is reasonable. With Citrix servers, the ratio is 6:1 due to greater client traffic. Dell Computer Corp. suggests a 5:1 to 8:1 consolidation ratio.

How NAS fits into different storage environments

Windows Storage Server 2003 and Beyond: WinFS
This past September's release of Microsoft's Windows Storage Server 2003 gave an added boost to the network-attached storage (NAS) market. Storage Server 2003 is the latest version of Windows stripped down, and is optimized for file and print serving and packed with a variety of storage goodies such as volume shadow copy services (VSS), distributed file services and file replication services. Since its release, vendors such as Iomega at the low end of the NAS market to EMC at the high end-- and many in-between--have rushed to bring out NAS products built around Windows Storage Server 2003.

"Customers have been asking for this. They want to move to NAS and consolidate their Windows file servers on the Microsoft platform. Previously, they had to use proprietary NAS operating systems like NetApp or EMC," says Nancy Marrone-Hurley, senior analyst, Enterprise Storage Group, Milford, MA. Now they can manage NAS using their Windows skills and familiar tools. Longhorn, the next generation of the Windows operation system, will include what amounts to the next generation of the Microsoft Storage Server, called WinFS. According to early Longhorn documentation, WinFS is an active storage platform for organizing, searching and sharing a variety of information. It defines a rich data model, builds on top of a relational storage engine, supports a flexible programming model and provides a set of data services for monitoring, managing and manipulating either file-based or non-file data. Microsoft describes WinFS as "more than just a new file system, because it also deals with non-file data, such as personal contacts, event calendars and e-mail messages." Essentially a programmable storage platform, WinFS will expose relational-, object-oriented- and XML-based APIs for access to the underlying data store. It will also support data access through the traditional Win32 File System API. The WinFS programming model is extensible in that user-defined schemas and data types can be incorporated to serve special-purpose needs, according to the documentation. The benefits of WinFS will result from the many ways users and applications can store and access the data. As Microsoft puts it: WinFS "enables users to organize, find and share information in a more intuitive and logical way." The big question for the rest of the storage industry is how open Microsoft will make WinFS.

Altera Corp., a programmable chip manufacturer in San Jose, CA, consolidates storage for a mix of Windows and Unix servers at a ratio of 10:1, reports Rosemary Nahrvar, senior IS manager. "We got rid of a lot of old file and print servers and departmental servers and put it all on BlueArc NAS with 8TB," she says. The company recently purchased a second BlueArc device. "It is easy and much cheaper to add space--about $25,000 for 1TB using a BlueArc ATA array," she says. Altera also runs an EMC-based SAN for its Oracle database and ERP system.

Agere Systems Inc., an integrated circuit manufacturer based in Allentown, PA, embarked on its current NAS strategy in early 2003 with the goal of consolidating about 20 Unix file servers while providing 30TB to 40TB of storage capacity. It installed Network Appliance Inc. (NetApp) filers and used tools from Rainfinity to move data from its old filers to the new NAS boxes. Today, the company is reducing the number of NAS devices by replacing older NetApp filers with a larger model as the leases for the existing devices expire. "Over time, we end up with fewer--but bigger--filers, which lowers our maintenance and support costs and gives us a better cost per megabyte," says Alan Cohen, Agere IT architect.

At Houston Energy, an independent offshore oil and gas exploration company, the plan from the start was to consolidate nine storage devices in an EMC Celerra NAS device. The goal of the consolidation is stability, scalability, manageability and data protection. "We replaced nine old SCSI disk arrays controlled by Unix servers and some other old NAS products with a new 8.6TB Celerra system," says Paul Davis, MIS network administrator.

Microsoft makes an enterprise play
Although Windows has been traditionally relegated to the low end of NAS, Microsoft is making a determined effort to move Windows up the storage food chain with Windows Storage Server 2003 (see "Windows Storage Server 2003 and beyond: WinFS"). "In big enterprises, Windows was not the first choice for NAS consolidation, but with clustering that can change," says Mike Fisch, director of storage and networking at The Clipper Group, Wellesley, MA.

Windows NAS may be suitable for midsized enterprises, "but at the high end, enterprises will still go to SAN for consolidation," says Peter Pawlak, lead analyst, Directions on Microsoft, Kirkland, WA.

Consolidation of Windows file and print servers is a natural for Windows-based NAS. Among dedicated Windows shops--especially at the low end--Windows Storage Server 2003 should be warmly welcomed. "I haven't seen it yet, but I'm looking forward to Storage Server 2003," says Tim Killion, IT director at BRE Commercial, a San Diego real estate firm that runs Microsoft systems. The 125-person firm uses NAS devices from Dell, Iomega Corp. and Quantum Corp.

Dell insists that Windows Storage Server can scale sufficiently for serious enterprise storage consolidation. It will offer the Microsoft operating system with PowerVault systems that can handle up to 16TB with SCSI and up to 40TB with Fibre Channel (FC). "Yes, it can be entry level, but it also is robust and can scale to eight-way clustering," says John Pate, Dell product marketing manager.

EMC is also supporting Windows Storage Server 2003 for its small NetWin NAS products. "It's intended to be used in a core-edge deployment model, like you find with branch offices," says Chuck Hollis, EMC's vice president of storage platform marketing. It would require a board upgrade, however, to scale from NetWin NAS to EMC's Clariion line. NetWin works for organizations that want a low-cost, cookie-cutter storage solution they can quickly deploy at multiple satellite offices.

Adding advanced features to NAS
Vendors are loading advanced features into their NAS products. Windows Storage Server 2003 includes not only volume shadow copy for fast file restoration from snapshots but multipath I/O, iSCSI support, the ability to act as a gateway to the SAN, a new Web management interface and more. Many of these features plus others, such as a multioperating system and multiprotocol support, have long been available in the non-Windows world from NAS vendors.

The most popular features include high-availability clustering and point-in-time snapshots. Winphoria Networks, a division of GTSS Motorola, recently added a multiprotocol NAS storage array from Winchester Systems and makes regular use of NAS snapshots. "We use a snapshot for online backup of the file system," says David Heafey, IT manager at Winphoria. The snapshot is stored nightly on a second NAS device, where it maintains about one week of snapshots online. Heafey expects the multiprotocol NAS device to be instrumental in any future migration from NAS to SAN.

Agere uses snapshots to provide short-term recovery for users who need to quickly restore a lost or corrupted file. "We also will run SnapMirror with specific applications for redundancy and disaster recovery," says Agere's Cohen. SnapMirror is NetApp's replication tool. For full data backup, Agere also uses Veritas' NetBackup in conjunction with the network data management protocol (NDMP)--an open protocol used to control data backup and recovery communications between primary and secondary storage in a heterogeneous network environment--to send data to a media server with tape attached.

Houston Energy mixes FC disk and low-cost ATA disk in its Clariion storage array. Network administrator Davis then uses EMC's SureSnap, a snapshot capability that comes with the EMC management console, along with basic NFS file transfer to move data between high-performance FC disk, economy FC disk and low-cost ATA disk--all within the same array.

Next-generation NAS
What will the next generation of network-attached storage (NAS) look like?

ExaGrid Systems, Westborough, MA, thinks it knows and is calling it Grid-Protected Storage. An architected solution, Grid-Protected Storage promises to deliver distributed, shareable storage with data protection. It integrates policy-driven backup and restore, disaster recovery, on-site and off-site vaulting and compliance archiving directly into primary storage. The product, according to the company, should result in lower costs and less complex data storage.

Arun Taneja, senior analyst at the Taneja Group, Hopkinton, MA, describes Grid-Protected Storage as a "self-managing, self-healing NAS product that scales simultaneously in the dimensions of capacity and performance and offers built-in data protection." In short, it combines a NAS filer with nearline storage for backup and recovery, HSM for policy-based file migration, self-management, content-addressable storage and disaster recovery tools. But lest you think it does everything--the equivalent of a storage Swiss Army knife--it does nothing for SAN block-level storage and is unlikely to beat high-end products from NAS industry leaders in terms of high speed, Taneja says.

NAS heads
Originally, NAS products were primarily appliances that combined hardware, the filer operating system and storage arrays in a single box. These devices can still be found at the low-end and the midrange markets. But increasingly, vendors allow the NAS operating system to be separated from the storage arrays to create a NAS head. NAS heads can be used as gateways to a consolidated SAN that provides both file- and block-level storage.

It seems like a good idea, but "today's NAS customers don't want all that. They want NAS because it is simple, easy and cheap," GlassHouse's Foskett says. Should storage become a centralized utility, the NAS head would offer a way to leverage block storage for files. But the storage utility isn't a reality today.

Still, NAS heads may yet gain traction. "It gives you a nice front end to both files and blocks on the back end. And as iSCSI takes hold, there will be less of a need to differentiate file and block storage," says Scott Robinson, CTO, DataLink Corp., a storage integrator based in Chanhassen, MN. When that day comes, the NAS head would open up interesting opportunities in terms of the use of primary and secondary storage tiers and information life cycle management (ILM).

Today most companies are not taking advantage of all the capabilities vendors are packing into their NAS products, although the best products in the market can almost match SAN technology in features and capability. To them, NAS remains easy and cheap file storage--period. And despite being widely deployed in the enterprise, NAS remains a stealth technology while SANs attract the most attention.

This was first published in March 2004

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