Cut Cost and Hassles with Network Attached Storage

By Lowell Rapaport

There is a name for the system administrator’s pain and it is called “system upgrade.” To put it bluntly, system administrators hate it because every time you add something to a system you run the risk of breaking something. Network attached storage (NAS) is sold on the premise that you don’t need to upgrade your system or add a full-blown NT server to make more storage available on a network.

NAS vendors marry a storage subsystem to just enough computing power to get on-line and to assign user access. NAS devices are as plug-and-play as a network device can get and, except for routine administrative functions such as creating new users, are generally maintenance free. NAS operating systems can run on any hardware and act as a bridge between your network — whether it is Ethernet, SAN or some other technology — and storage devices such as RAIDs, jukeboxes or libraries. You get all the advantages of a full operating system with little of the complexity and cost. This is the promise of Network Attached Storage.

Libraries in particular can benefit from NAS because they are among the most complicated storage devices typically deployed on a network. Allstor (www.allstor-sw.com) was one of the first companies to market a network-attached solution for CD libraries. The company’s early head start has led to a product line of four NetReady devices. They have an Integration Module, an NAS device that mounts inside a jukebox in place of a drive, and three externally mounted jukebox servers ranging from the small NetReady for Workgroups to the largest NetReady Cluster Server, which is equipped with 100 gigabytes (GB) of disk cache.

Where to Put NAS Since NAS is such an excellent substitute for most forms of server-attached storage, you might think that NAS devices should be in a central location alongside conventional servers. However, the only reason conventional servers are centrally located is to simplify maintenance and administration. Placing NAS storage in a central location places an undue burden on your network while missing the advantage of their remote administration and low-maintenance features. Since most NAS devices require little or no maintenance, they can be placed in high-traffic areas alongside laser printers or hubs serving individual workgroups. By placing the NAS on the same subnet as the workgroup to which it is assigned, network administrators can maintain high network performance without having to install high-speed network lines or expensive switches. NAS maintenance is eased by the fact that they all support remote administration via a Web browser.

NetReady devices are purchased by end users and by storage vendors who incorporate them into their own storage devices. One customer is Allstor’s parent company, Plasmon (www.plasmon.com), which uses the NetReady for Workgroups in conjunction with its (CD, DVD & MO) jukeboxes. End-user customers for the NetReady are split between large enterprises, where system administrators try to avoid server proliferation, and small companies, where system administrators try to avoid i nstalling complex servers altogether.

Installation, setup and administration are a strong suit of the NetReady. They are self-configuring, and their BSD-derived Osprey operating system can speak nearly all network protocols, including high-end ones like asynchronous transfer mode (ATM). This suits them to large enterprises and high speed networks. As icing on the cake, the Osprey OS can be OEMed. Allstor publishes a full API for developers who wish to build NAS devices incorporating Web, FTP, Exchange and e-mail servers.

Due this month from Cygnet (www.cygnet.com) is a Linux-based NAS server designed for Cygnet’s Infinidisc jukeboxes. Unlike the NetReady, Cygnet’s product is designed specifically for their jukebox hardware. Since it is based on Linux, the software is completely open source.

Cygnet is going straight to DVD-RAM support with their NAS device. The DVD-RAM drives in their jukeboxes will read CD, CD-R, DVD, DVD-R and DVD-RAM disks. A 500-slot jukebox with four drives will store 1.3 terabytes (TB) of data for $42,000, including the NAS option.

According to Wayne Augsburger, Cygnet’s vice president of sales and marketing, the NAS feature adds about $10,000 to the price of a jukebox. “It’s cost effective though,” says Augsburger, explaining that it replaces the need for traditional jukebox software. “The jukebox management software for a 500-slot jukebox would cost at least $11,000 to $13,000. And that’s not including the cost of a server, setup and maintenance. Using Linux helps keep our costs down even further.”

Operating Systems Add Flexibility

The presence of NAS operating systems leads to some interesting possibilities. Other applications can be run on top of a NAS OS to operate jukeboxes, tape libraries and other storage devices. Add HSM to a NAS device and you can combine different storage devices such as a RAID subsystem and a tape library. Although this can be done now with conventional servers and storage management software, NAS technology could potentially accomplish the same thing at lower cost.

One NAS operating system with great potential was acquired by Quantum (www.quantum.com) when it purchased Meridian Data earlier this year. In addition to its network-attached CD-ROM tower line, Meridian offered a low-end NAS device called the Snap Server. The Snap Server is essentially a thin server with one or two IDE disk drives. The key to the technology is the Snap OS, a simplified version of Unix derived from BSD.

According to Erich Flynn, director of marketing for what is now Quantum’s Snap division, the Snap OS is poised to replace traditional Windows servers for all but a few applications. “The market for storage servers is expected to quadruple by 2003,” he says. “Thin servers like the Snap OS can save the IT industry billions in installation and long-term management costs when compared to traditional servers.”

When Not to Use NAS One of the most compelling arguments for NAS is that you can use it in place of conventional server-based storage with no penalties in speed or features. If NAS were universally sufficient for all business needs, there would be no need for any other type of storage. But there are situations when NAS is not suitable. Don’t use NAS to store databases. A database is an extremely active file, more active even than the archives to which it refers. In order to run sorts and initiate searches, a server has to have direct access to a database. Since network connections are generally too slow for these operations, database storage should be connected directly to the server. This holds true for any application that directly manipulates files on disk. Don’t use NAS for sensitive data. The NAS model requires that the storage device be mounted to a network. While all NAS devices include strong security measures, it is generally recommended that the most sensitive data not be mounted to a network. Storage attached to a computer can be worked on by users directly from the computer without exposing the data to a less-secure network.

An operating system like the Snap OS can be the basis for all sorts of interesting NAS storage devices. (Quantum says it will tap this promise by OEMing their OS.) Combine the OS with library management software and it can be used with CD and tape libraries with and without RAID front ends. Add a Java Virtual Machine and it can be used as a Web server appliance or a backup server.

NAS operating systems are generally reduced to the barest essentials. There is no GUI apart from an HTML interface, and there are no common system services, like print drivers or multimedia applications. The hardware for the OS is simplified as well, requiring only one or two I/O drivers. Networking capability is extensive however, as engineers can take the time to see to it that all network protocols are supported, no matter how obscure.

As an example of how extensible NAS can be, ADIC (www.adic.com) is planning to ship an NAS module for their terabyte-range Scaler series of tape libraries. Set to ship in January, ADIC’s solution will mount a tape library to a network as a single massive storage volume. The largest of these libraries can reach more than two dozen terabytes, making them the largest NAS devices of all. ADIC will initially make their DLT-based libraries network attached, with AIT to follow later.

ADIC’s firmware OS is fully proprietary and is not intended to operate other kinds of storage devices in tandem with their libraries. This is not a problem, according to Bryce Hein, ADIC’s product marketing manager.

“Tape libraries are generally used periodically rather than continuously, and data is moved to and from them in large blocks,” Hein says, explaining that this diminishes the need for a separate RAID front end. “We are still working out many details, like how much hard drive cache to install. Libraries that will be continuously accessed will need large disk caches, while those used less often or by fewer users can get away with a smaller cache.”

Moving RAID Toward NAS

NAS tape libraries and jukeboxes can be placed anywhere on a network. If they are accessed infrequently, they can be located more centrally — a fitting placement for such large-capacity storage devices. Active files, commonly kept on RAID subsystems, can also be attached directly to a network, giving you both the advantages of NAS and the scalability and reliability advantages of your typical RAID subsystem.

The Netforce 100 from Procom (www.procom.com) is a network attached RAID system. Like many RAID subsystems, it possesses hot swappable hard drives and redundant power supplies and cooling systems. It applies RAID level 5 to its six IDE hard drives and has a capacity of up to 150 GB. And at prices between $4,000 and $15,000, it is inexpensive enough for most mid-sized workgroups within an organization. Unlike most RAID subsystems, you can administer the Netforce remotely with a Web browser and locate it directly on the subnet where it is being used.

Procom also makes an enterprise-wide network attached RAID, the Netforce 2000. Befitting a RAID that can accommodate between 10 and 100 drives, you can select any RAID level and group the drives into multiple arrays —all through a browser interface. The top-of-the-line Netforce 2500 and 2600 add symmetric fault tolerance. There is no single point of failure for the system.

At the high-end of RAID subsystems is MTI’s new Vivant trio: V10, V20, and V30. The V10 and V20 scale up to 3 TB, while the V30 hits 9.6 TB. MTI’s Vivant subsystems can be administered with a Web browser or with a proprietary Windows NT client.

Network attached RAID systems like these from Procom and MTI bridge the gap between NAS and storage area networks (SANs). Standard options for them include gigabit ethernet. MTI’s Vivant NAS RAID subsystems even have multiple connectors so they can be on regular ethernets and fibre-channel-based SANs at the same time. Their NAS software provides a model for how SANs, still an immature technology, could operate.

Network attached storage reflects a growing trend toward more intelligent peripherals. “As more intelligence is built into the storage server, application servers become more of a commodity item,” says Kevin Liebl, vice president of marketing for MTI. The long-term goal will be to replace traditional server based storage. Server computers running Windows NT or Unix will be given completely over to server applications and databases, with the grunt work of storage and retrieval left to NAS devices designed for the task.

Product Information Allstor-NetReady Rancho Santa Margarita, CA 949-766-3200 Description: Network attached jukebox servers Network interface: 10/100 Base T, ATM, Token Ring Protocols: IPX/SPX TCP/IP, Appletalk (limited) Comment: There are four NetReady configurations: an internal unit for OEMs and three external units for end users. Top-of-the-line NetReady Cluster server includes high availability options such as clustering and redundant power and cooling. Supports CD, DVD, MO and WORM jukeboxes. Price: NetReady Cluster Server $13,600; NetReady for Business $7,700; NetReady for Workgroups $5,000; NetReady Integration model for OEMs only $3,200 ProductInfo #240 Cygnet-NAS Module Milpitas, CA 408-954-1800 Description: Network attached jukebox server Network Interface: 10/100 Base T Protocols: IPX/SPX, TCP/IP, Appletalk Comment: Linux-based firmware running on an x86 mother board. Shipping with Cygnet’s Infinidisc DVD-RAM jukeboxes beginning this month. Price: Estimated to add about $10,000 to the cost of a jukebox, though it eliminates management software costs. ProductInfo #241 Quantum Snap OS Scotts Valley, CA 831-438-3100 Description: NAS operating system Network interface: NA Network protocols: TCP/IP, IPX/SPX, Appletalk Comment: The OS for Quantum’s Snap Servers consumes less than 3 MB storage and will run with less than 4 MB memory. Quantum says it plans to OEM the OS. Price: NA ProductInfo #242 MTI-Vivant Anaheim, CA 714-970-0300 Description: Network attached RAID subsystems Network interface: 10/100/1000 Base T, fibre channel Network protocols: IPX/SPX, TCP/IP Comment: Bridges the gap between NAS and SAN, functioning on both topologies. All RAID levels are available in multiple configurations. The V10 and V20 scale up to 3 TB, while the V30 goes up to 9.6 TB. Price: $173,000 - $1.5 million ProductInfo #243 ADIC Scaler NAS Module Redmond, WA 425-881-8004 Description: NAS module for Tape Libraries Network interface: 10/100/1000 Base T (Gigabit ethernet is due later on) Network protocols: TCP/IP Comment: To be introduced in January as part of a new tape library, the six-drive, 60-slot Scaler 100 (2.4 TB equipped with DLT-8000 drives). An external version will be made available for other Scaler libraries. Price: Expected to add about $10,000 to the cost of a library. ProductInfo #244 Procom Netforce 100/2000 Irvine, CA 949-852-1000 Description: Network attached RAID subsystems Network interface: 10/100 Base T, 1000 Base T (Netforce 2000 only) Network protocols: TCP/IP Comment: Netforce 100 supports RAID level 5 on six IDE drives. Windows networks only. Supports workgroups up to 50 users. Netforce 2000 line includes Netforce 2000 (10 drives), 2200 and 2500 (50 drives each), and the 2600 (100 drives). All RAID levels supported. Price: Netforce 100 $4,000 - $15,000; Netforce 2000 Series $20,000 - $250,000 depending on drive capacity. ProductInfo #245