In my September 5 Storage column, I wrote about Network Appliance (NetApp). Several readers wrote to chide me for adding an "s" to the name. Good point. The Sunnyvale, California, company is quietly moving up the storage vendor ladder with some good growth numbers, although its name remains singular. According to the company, NetApp posted a $579 million net income for the fourth quarter of 1999. International Data Corporation (IDC) predicts that the Network Attached Storage (NAS) market will experience a compound annual growth rate of 66 percent, growing from $850 million in 1999 to $6.57 billion by 2003. Before these numbers were posted, NetApp was ranked number 11 in the area of disks shipped; the new numbers make it number 7, just behind Dell. Given that NetApp is a storage-only vendor and doesn't have captive disk to peddle, that's not bad.
NetApp focuses on NAS technology. Although in the survey we ran in Storage UPDATE, our readers didn't designate NAS a key technology, companies often do choose NAS to solve immediate problems. Maybe that's why NAS is popular in quick-growth companies such as ISPs and Dot-Coms. In any case, I'm a NAS fan. You plug in a NAS device, the internal OS goes over the network and grabs an IP address, and the device shows up in your Network Neighborhood as if it were a server. At least most NAS boxes (e.g., the Quantum—nee Meridian—SnapServer!) work that way.
Typically, some software is bundled with a NAS device—perhaps a small embedded Web server to help manage the device from anywhere via a browser or, in NetApp's case, utilities such as the SnapMirror snapshot program that lets you save metadata to reconstruct your data in case of a failure. Although you can use it to reconstruct a history of your data files, I'm not a snapshot technology fan. Extra disk is expensive, but I still believe that mirrored systems backed up by tape offer the best enterprise-class storage solution.
When I visited NetApp, Mark Santora, senior vice president of marketing, gave me the NetApp view of the storage world: Successful companies in the industry are "decomposing" the server of old. And just as Cisco took routing from the server, NetApp is taking file services. Santora claims that NetApp's file system is the only one that intrinsically "understands" RAID geometry and that the company has reduced the file systems once controlled by code monsters such as Solaris and Windows to the optimized Write Anywhere File Layout (WAFL) OS at 300K. Doing so lets NetApp boxes run on modest servers (e.g., 90MHz Pentium servers).
Interestingly, the NetApp boxes run RAID 4; some contain up to 52 disks in a single volume. The systems use a large write-through cache, as does any serious enterprise-storage solution, and parity is written to a single disk. Reads can be accessed randomly, while writes go to each disk in the RAID array at the same time. This system eliminates the hot spot that occurs on RAID 4 parity disks that use standard file systems. Santora claims that 38 percent of a standard network operating system's (NOS's) activity is file system related. So stripping off the file services gives you back 38 percent of your server—or 38 percent more server life.
NAS serves up files, which differentiates it from block-oriented devices. Protocols that run on top of the WAFL OS/Data ONTAP 6.0 layer include Document Attribute Format Specification (DAFS), Common Internet File System (CIFS), NFS filers; HTTP stacks; and cache, Message Management System (MMS), Real Time Streaming Protocol (RTSP), and Internet Content Adaptation Protocol (iCAP) network caching services. NetApp has just released into the public domain its DAFS file system, and Infiniband is DAFS enabled. NetApp boxes fully meet Windows NT/UNIX cross-platform needs. The OS handles the Windows NT-to-UNIX security mechanism transparently.
Unfortunately, NetApp's boxes don't scale, or at least the company is having trouble scaling them. Any new "s" in name will have to be for size. The company will soon release an F840 system that will offer a 4.5TB disk capacity; two boxes can be clustered to create a 9TB system. In the past, you could use these clusters only for mirroring, but the new software lets you use them as a 9TB storage system. According to NetApp, in 2 months, a software upgrade will push this system to 6TB, for a 12TB total, letting the new offerings compete in the high-midrange class of storage systems. And, considering that the large frames from EMC, IBM, and HP/Hitachi all mirror, NetApp's new system competes with devices of that size as well. (Only Auspex and Celerra really compete with NetApp in their market.)
NetApp also has a caching product, and—with the company's recent acquisition of Web Manage—the company can stage data files across distributed enterprises and the Internet using just NetApp file systems. (Akamai did extremely well with caching last year, and Novell hopes to ride its caching product back to health.) For more about NetApp, read the white papers at the following four Web sites:
Using the NetApp Filer in Microsoft Windows Networking Environments
(Windows 2000 isn't covered.)
CIFS Authentication and Security White Paper
An NFS File Server Appliance
(Although dated 1995, Hitz's paper is still a valuable primer on the NetApp architecture.)
- Multiprotocol Data Access: NFS, CIFS, and HTTP