Pieces of the iSCSI Puzzle Starting to Fall into Place

In general, most of the recent hype about new storage technologies has focused on big-picture elements such as storage network technology and storage management applications. But in order for new technologies to meet or exceed expectations, the technology must expand to the edge of the network. You must incorporate both the desktop clients and the target devices (i.e., disk drives and tape drives) into new storage infrastructures. If the desktop clients and target devices aren't available, end users will shy away from incorporating the new host technology. Over the past couple of months, iSCSI client and target-device development has begun to accelerate, paving the way for iSCSI to make its presence felt in the enterprise by early 2004, if not sooner.

Although market research company Gartner anticipates that by 2006 iSCSI will connect nearly 1.5 million servers to Storage Area Networks (SANs), the adoption of iSCSI technology to date has been slower than anticipated. The logic behind the technology is compelling. By using standard Ethernet TCP/IP networks, iSCSI lets companies build low-cost storage networks at a fraction of the cost of alternative technologies. By some estimates, implementing iSCSI networks could cost as much as 75 percent less than using Fibre Channel technology. The decrease in expense means more companies, particularly smaller companies, could be willing to try iSCSI.

In addition to providing a lower cost alternative to Fibre Channel in creating SANs, iSCSI has several other applications. You can use iSCSI to link independent Fibre Channel SANs, in data replication and data mirroring applications, for offsite data storage and disaster-recovery settings, and you can apply the technology in almost any scenario in which high performance isn't a concern.

Despite its obvious attractions, several barriers have slowed the widespread adoption of iSCSI. Although major vendors have given lip service to their support of iSCSI, their commitment to and follow through in releasing compatible products hasn't been as robust as might be desired. One major barrier facing vendors was that the iSCSI standard wasn't finalized at the time they were trying to release compatible products. Another concern, as stated by Peter Cmaylo, vice president of business development at iStor Networks, which has released new OEM-oriented technology in this area, is that, "there has been a lot of work on the host side but the target side has been neglected."

iSCSI is finally starting to overcome those barriers. The first major development came in February when the Internet Engineering Task Force (IETF) approved the iSCSI standard. The finalization of the standard lets manufacturers in all sectors of the storage market develop products that are compatible through their adherence to the standard.

In a second major development, this month, Microsoft will release free iSCSI software drivers. Although drivers are already available from IBM, Cisco Systems, and Intel, Microsoft's support is crucial to iSCSI's success. The Microsoft drivers support data encryption, the Internet Storage Name Service (iSNS) management, and an architecture for incorporating hardware from different vendors.

Reportedly, more than 60 companies are using the Microsoft iSCSI protocols to create hardware and software products. Microsoft has launched a logo program for hardware vendors that use the company's protocols. And, along with the University of New Hampshire and the Storage Networking Industry Association (SNIA), Microsoft is conducting interoperability tests with iSCSI technology from other vendors.

Another part of the iSCSI puzzle that's starting to fall into place is the availability of native iSCSI target devices. Although IBM was first to market with an iSCSI disk array, the company pulled its product from the market last year. At the end of last year, Eurologic unveiled an iSCSI disk array, which the company recently upgraded. In January, EqualLogic previewed an iSCSI disk array. And last month, iStor Networks unveiled technology that can aggregate as many as eight independent IP storage networks into a single system. The technology expands the number of Serial ATA (SATA) disk drives in the same storage domain from 16 to 128, and, according to iStor officials, helps iSCSI overcome storage capacity and bandwidth limitations.

As more target devices emerge, it could be as easy to set up a SAN as it is to set up a home area network. When that happens, iSCSI will have lived up to its promise. By early next year, however, iSCSI should make an impact in the enterprise arena.