The convergence of networking and storage tools recently has taken an interesting turn. Much of the debate has focused on the merits of inexpensive NAS (network-attached storage) versus expensive, high-performance SANs (storage area networks). IT leaders whose enterprises run demanding applications want to use SAN technologies but have found it difficult to build storage networks that are as far-reaching and easily managed as their data networks.

Enter the storage router. Essentially a device that enables users to connect switched-storage environments on a standard data network, the storage router may be the best thing to happen to storage since the introduction of RAID. In practice, many of the boxes debuting in this space will support connections to Fibre Channel switches, SCSI devices, or both, such as drive arrays and tape libraries, on the one hand, and will feature a Gigabit Ethernet interface on the other.

Some customers might miss an important point here. Storage routers are not about directly connecting devices to the local network or even to the enterprise backbone; they're about building a separate network infrastructure for the storage network. Networking and storage vendors (Brocade Communications Systems Inc., EMC Corp., Cisco Systems Inc., and others) emphasize using the networking technology already at hand -- which, hopefully, your staff already understands well -- to realize a quick return on your technology investment.

The current high end of networking technology offers plenty of room to grow for even the most storage-intensive applications. With 10G Ethernet a couple of years away from general use, vendors have an even greater need for problems that require high-speed solutions. Storage networking may well be the killer app that drives the sale of Gigabit Ethernet and faster equipment for the foreseeable future. This could prove a lifesaver for vendors in the absence of a viable desktop market for speeds beyond Fast Ethernet's 100Mbps.

Cisco is taking a leading role in the development of storage routing technology and, more specifically, the iSCSI (Internet SCSI) protocol that allows block-oriented technologies such as SCSI to use IP's packet-based transport.

After some hands-on experience in Cisco's San Jose, Calif., lab with its latest entry in the field, we can comfortably say the technology is ready for prime time, albeit not without its catches. Customers seem to think so, too: The production line has been rolling since April, and two months later, Cisco still wasn't able to set aside any review units for us.

The storage networking market is one of the few bright spots in the otherwise dismal networking industry, partially because the standards and technology have all come together. Prior attempts at networking SANs that involved encapsulating Fibre Channel and SCSI data in IP packets haven't panned out, in part because the performance didn't measure up and because Fibre Channel devices have traditionally been configured as a series of loops,rather than in a true network. (Earlier this year, we discussed some physical issues behind storage networks; see "Future-proof your storage environment" at www.infoworld.com/printlinks.) Now, iSCSI and its counterpart iFCP (Internet Fibre Channel Protocol) are taking advantage of the evolution of SCSI protocols and using Internet protocols to extend the reach of storage networks beyond the limitations of existing Fibre Channel and SCSI technology.

Leading storage vendors such as Adaptec Inc., Brocade, and EMC are rushing to support iSCSI, iFCP, and iSNS (Internet Storage Naming Service), the Internet Engineering Task Force's trio of storage networking protocols, which are successfully evolving from vendor white papers into real products. But it seems most networking devices are going to be built by traditional networking companies or upstarts specializing in storage networks. One of the latter companies to watch is Nishan Systems, which offers three IP storage devices aimed at environments ranging from local to metropolitan networks.

Storage networks are the new frontier of computer networking and may be the most important investment that businesses make in the next few years. The idea of shared storage for clustering systems is nothing new, but building the enterprise storage network has been difficult until now because the Fibre Channel and SCSI protocol sets don't themselves network easily. Cisco's SN 5420 and competing devices address these failings and merit serious consideration.

» posted by abennett

InfoWorld

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