Even though many organizations still rely on direct attached disk storage, its heyday is inexorably receding into the past. According to industry research firm IDC, networked storage has already crossed over the 50% threshold in terms of its share of the total disk storage systems market. So, the question isn't whether or not you will configure your storage for shared access over a network. Rather, it's how you will. Your design decisions - now and in the foreseeable future - will likely be influenced by two parallel developments: 1) the evolution of IP storage technologies; 2) the evolving price point differences among various storage options.
IP Storage: Maybe Now, Definitely Later
Fluctuating price points for various storage networking technologies expand end users' options. At the same time, they complicate purchasing strategies. For example, a year or so ago, IP-based storage solutions, particularly those enabled by the iSCSI (Internet small computer system interface) protocol, were commonly regarded as potentially low-cost alternatives to Fibre Channel for deploying storage area networks (SANs). But, the recent emergence of low-cost ATA (advanced technology attachment)-based hard disk drives has helped already budget-friendly NAS (network attached storage) and, especially, Fibre Channel SANs (traditionally not budget-friendly) become more attractive to midmarket customers. "There has been a whirlwind change - from Fibre Channel pricing to ATA pricing," says Andy Pratt, president and CEO of storage solutions provider Unique Digital, Inc. (Houston). "That is reflected in lower priced components in vanilla NAS and SAN configurations."
Although Mark Nagaitis, HP's (Palo Alto, CA) director of product marketing for the infrastructure and NAS division, also sees promise in IP storage as a complementary SAN technology, he advises customers to be wary of claims that it is always a lower cost alternative to Fibre Channel. "Fibre Channel is becoming less costly and complex to implement," he says. "And, despite the common assumption that you can run IP storage over your existing Ethernet network, IP storage still often requires a separate network because of security requirements. But, those problems will eventually be resolved." Pratt agrees that iSCSI isn't yet a plug and play proposition. "Network and storage infrastructures are always loaded with junk that creates chatter and disruptions. So, you'll still need to change a lot of your infrastructure if you want to bring in iSCSI." That said, Pratt believes faster Ethernet networks will eventually drive widespread adoption of IP storage. Says Pratt, "When 10 GB Ethernet really takes off, a trend we expect to happen by 2005, IP SANs will also take off."
In addition to pulling storage into networked configurations, customers will increasingly seek disaster recovery (DR) solutions. Again, the evolution of IP storage will play a major role. "Until there are more iSCSI gateway devices on the market, the FCIP [Fibre Channel over IP] protocol will be widely used to extend SAN capabilities across sites," says Scott Drummond, product director for storage marketing at IBM (Armonk, NY). "But, we're already seeing switch vendors coming out with both Fibre Channel over IP and iSCSI service modules." Such devices will not only help in replicating SANs for DR configurations, they will also offer flexibility across LANs and WANs (wide area networks). Says Nagaitis, "Routers that have Fibre Channel coming out one side and IP out the other allow you to take departmental servers that don't demand Fibre Channel performance and give them access to centralized storage."
Hardware: Manage It Or Replace It?
As your networked storage infrastructure grows, so will the complexity of managing that growth. At some point, you'll be faced with a key purchasing decision: Should you bring on increasingly powerful software management tools to deal with the diversity of storage hardware bought piecemeal, over time? Or, should you periodically replace your hardware, eventually eliminating most of the complexity-inducing heterogeneity? Stated in that way, the either/or is, of course, a bit reductive. Managing your networked storage will require savvy use of both hardware and software. Nonetheless, generally speaking, you'll end up leaning toward one or the other approach: hardware replacement mentality or software management.
Customers often base storage purchases on a "take the best deal at the moment" philosophy. That tendency can make heterogeneity - and a reliance on sophisticated software automation - inevitable. "Companies aren't pulling out old architecture and replacing it with new architecture at the rate they were three or four years ago," says HP's Nagaitis. "They want to add shared storage functionality to their existing environments even as those environments evolve." IBM's Drummond agrees, noting increased storage complexity at growing companies. "Companies are never likely to have a clean environment because it's difficult for them to predict the vagaries of systems brought in via mergers and acquisitions," he says. That's why Drummond sees the need for device management software that can handle file sharing and storage allocation across multiple platforms. "We studied typical storage administrators in diverse, open systems environments," Drummond says. "They spent an inordinate amount of administrative time creating and managing virtual volumes in shared pools."
While Unique Digital's Pratt doesn't discount the value of management software, he's definitely not quick to worry about the challenge of managing vastly heterogeneous environments. Pratt believes we are witnessing a dramatic change in the purchasing landscape - a change precipitated by steadily decreasing hardware prices. "We're moving into a disposable, commodity computing scenario. If something breaks, you throw it in the trash," says Pratt. "Customers are buying back into the notion of having limited vendors in the storage infrastructure. We show them how easy it is to manage a storage network from a single console if they get rid of the mixed breeds."