Storage Focus: The Outlook for IP SANs
iSCSI provides a means to transport native SCSI commands over TCP/IP, allowing storage arrays to be shared over the Internet Protocol (IP) and storage area networks (SANs) to expand by utilizing Gigabit Ethernet (GbE) networks. Earlier this year, the Internet Engineering Task Force (IETF) approved the specification as a viable standard.
However, the protocol faces potential competition from — or, at the very least, potential friction with — the Fibre Channel protocol prevalent in most SANs today. And while some industry experts believe iSCSI will have an eye-opening effect on the storage industry as a whole, others feel that it will be nothing more than “business as usual.”
“I don’t see IP-based SANs and Fibre Channel (FC) SANs as competing with one another, but rather as complementing one another,” says Shaul Gal-Oz, CEO at SANRAD. He adds that even though IP-based SANs range in price from 2 to 6 cents per MB, a single path, non-redundant basic 2TB IP SAN for 20 servers costs approximately $40K.
“However, if you look at that same capacity, but need high performance, multi-pathing, and active/active fail-over, the cost for the entire package including host HBAs, management, connectivity, and high performance storage quickly rises to about $120K,” he continues. “With the higher end IP SAN, you basically have all the same features as a traditional FC SAN, and it can easily scale to 20 TB or higher.” Gal-Oz cites, as an example, the fact that a complete 8TB SAN would cost $160K for everything.
Gal-Oz believes that today's FC SANs address high performance, while IP-based SANs address simplicity, cost, and flexibility. One of the biggest misconceptions about IP-based SANs, according to Gal-Oz, is that they don’t have the same features as FC SANs. However, the reality is that IP SANs have almost completely closed the gap in terms of offering the same capabilities.
Diamond Lauffin, Nexsan's senior executive vice president, does not see IP-based SAN installations as having a great effect on the market in general, but he does believe the presence of such options could potentially be disruptive to the process of the purchase decisions made by corporate IT departments.
“In my experience, I see corporate IT investigating more aggressively the question of what can be done with IP — whether it is NAS or iSCSI,” he says. “The anticipation of 10 Gigabit Ethernet becoming available is opening up the minds of forward-looking IT engineers to explore the possibilities. At 100 Mbps Ethernet it was a dream. Even if it could have been practically accomplished, there was no interest in driving it.
"Now, at 1 Gigabit Ethernet, we have a different horizon and a level of practicality and acceptance. As we look toward 10 GbE, the landscape of what will be possible with IP changes greatly,” he concludes.