Depending on whom you ask, the iSCSI protocol, expected to be finalized in the next six months, either will play a significant role in the future of storage networking or will become just another unfulfilled technology promise. The debate raged on last week at the Storage Networking World conference.
Keeping iSCSI's momentum alive is the expectation that as many as 30 new iSCSI products from major players, such as Cisco Systems Inc., will arrive in the next six months. These products will include arrays that run the protocol natively.iSCSI already is appearing in some storage offerings. Last week at SNW, Cisco added a new feature called Network Boot to its SN 5400 Storage Router family. Network Boot allows a storage administrator to boot hundreds of servers from a disk subsystem located in a datacenter across an IP network, rather than booting each server individually.
This strong show of iSCSI support from storage vendors is "key validation of the iSCSI market," said Doug Ingraham, senior marketing manager at San Jose, Calif.-based Cisco's storage router business.
Additionally, both Microsoft Corp. and IBM Corp. have created native iSCSI drivers for their respective OSes, Windows and AIX. Ingraham said that Microsoft's support makes people less fearful of the new technology. "We're at the stage now where people are starting to get over the emotional, psychological factor [of adopting iSCSI]," he said. "We're moving away from 'iSCSI is neat' to showing how the technology is useful today."
But not everyone shares that optimism. "We're seeing zero interest in iSCSI within the datacenter," said Steve Beer, director of product marketing at Brocade Communications Systems Inc., an FC (Fibre Channel) switch vendor based in San Jose, Calif. "However there is high interested in using IP technologies to extend the SAN with a gateway over distance."iFCP (Internet Fibre Channel Protocol) and FCIP (Fibre Channel over IP) -- not iSCSI -- are the two protocols designed to extend and connect two or more FC-based SANs by encapsulating and sending the FC commands over an IP infrastructure. iSCSI, on the other hand, is heralded as an alternative to FC. It was designed to enable a server to access storage directly over an existing IP network, rather than over a separate, faster, and more costly FC network.
Beyond whether iSCSI will take off, the questions of where and when it will appear are up for debate.
"iSCSI is being targeted as an entry-level type SAN below the cost of FC-based SANs," said Mitchell Seigle, a senior marketing director with storage system technology provider LSI Logic Inc., in Milpitas, Calif. "However there may be a barrier to adoption as a network change must be made to take advantage of the technology."
The technology change of which Seigle spoke is Gigabit Ethernet equipment, which runs at 1Gbps, replacing Ethernet switches running at 100Mbps. "If a company has 1Gbps, then iSCSI will plug in and deliver on the promise," Seigle said. "But without [1Gbps], the cost savings are misleading."
Most observers agree that the market for iSCSI in the near future is small and midsize enterprises that can't afford to install and manage an FC-based SAN.
Jon William Toigo, a speaker at SNW and an independent consultant at Dunedin, Fla.-based Toigo Productions, noted that iSCSI works best with large-scale tape libraries, which smaller companies generally do not use.
Nevertheless, Toigo said, iSCSI stands to succeed because it leverages existing IP network infrastructure and thus does not require as significant an investment. "[iSCSI] is a protocol in search of a problem," he said. "In the end, it wins the day because of the enormity and entrenchment of IP networks."
The Cancer Therapy and Research Center, based in San Antonio, Texas, is already finding value in iSCSI. Using Cisco's SN 5428 Storage router and an existing IP infrastructure that connects the nonprofit company's primary datacenter with a backup location 22 miles away, CTRC can access patient records via the IP network if the primary location fails.
According to Reed Eicher, vice president and CIO at the CTRC, using IP storage along with Network Boot offers "significant cost savings over other networking technologies we could have used."
Cisco is not the only company flying the iSCSI flag. Adaptec Inc., Algoritech, Nishan Systems Inc., and StoneFly Networks Inc. are promoting iSCSI, and they expect other major storage vendors to join their cause.
Balaji Baktha, vice president of marketing at Milpitas, Calif.-based Adaptec's storage networking group, predicts more companies will join.
"iSCSI had been hyped out of proportion, but now all the support and specs -- the things that needed to be done -- are happening," Baktha said.
Fibre vendors aren't waiting for iSCSI
In the storage arena, 2002 opened with many promises, including the one that new technologies would ease the implementation of storage networks, as well as lower the costs. One of those new technologies was iSCSI, which uses ubiquitous TCP/IP networks to connect servers and storage devices, creating an alternative to previously unchallenged FC (Fibre Channel) technologies.
Chief among the objectives of iSCSI is to provide a less expensive network for storage, one that leverages existing infrastructure, such as Ethernet wiring and switches, and takes advantage of IT personnel's familiarity with deploying and managing TCP/IP. Although implementing an iSCSI SAN is likely to require additional hardware such as GbE (Gigabit Ethernet) NICs and multiprotocol switches, many analysts concur that the additional cost should be less than that of equivalent FC components.
Moreover, adopting TCP/IP for storage networks will overcome the distance limitation of FC and thus extend geographical reach without requiring expensive gear to convert one protocol to another along the way. Although processing TCP/IP takes a toll on servers' CPU resources, vendors such as Alacritech Inc., Adaptec, and Emulex Corp. are now shipping NICs that offload this burden, thereby removing an important impediment to iSCSI adoption.
By contrast, a mist surrounding target devices, such as protocol-capable disk arrays, is still blurring the iSCSI picture. With the noteworthy exception of IBM, no large vendor offers them. Although we have seen some interesting approaches from Okapi Software Inc., which proposes a software layer to make "iSCSI targets" from computers mounting traditional SCSI and ATA drives, the only alternative so far seems to be to use an iSCSI router, essentially a bridge device that provides access to traditional SCSI or FC arrays.iSCSI is still work in progress, and it probably will take years for all the pieces, including storage management and security, to fall into place. But even at this early stage iSCSI is having an impact on networked storage, in the form of driving down the cost of FC solutions. We've seen unmistakable signs that traditional Fibre vendors are striving to make their solutions less expensive to acquire and manage. So even if iSCSI becomes merely a niche technology, customers are already served.