Fiber channel's funeral march

Fiber Channel is the king of enterprise storage-area-network technologies. It's fast, it can handle long distances, and it's got strong vendor support.

ISCSI, however, is the heir apparent. When it comes to new SANs, add-ons to existing systems or departmental-level installations at large enterprises that have Fiber Channel, customers increasingly are choosing iSCSI. And when iSCSI over 10 Gigabit Ethernet comes online, the biggest remaining hurdle to adopting iSCSI storage -- its perceived slow performance -- will fall. At that point, iSCSI will become the storage interconnection transport of choice across the enterprise.

How soon until that happens? Analysts expect support for 10G Ethernet will be built into enterprise storage arrays and servers within the next three years. This means IT executives need to start learning about iSCSI now, begin asking their storage vendors about their iSCSI road maps and begin planning for an orderly migration to iSCSI.

The ascendance of iSCSI is backed by four reasons:

Cost. An iSCSI storage solution running on familiar Ethernet infrastructure costs a fraction of a high-end Fiber Channel solution in terms of the technology and the expertise needed to run it, IT experts say.

Staffing. Finding good Fiber Channel talent can be a challenge, and the scarcity drives up the cost. "It's hard to hire people with Fiber Channel expertise," says Andrew Reichman, an analyst with Forrester Research.

Compliance mandates. The growing list of industry and government mandates about the handling of data -- Sarbanes-Oxley, credit card regulations -- is driving companies to think out their storage and archiving policies carefully. The need to digitize documents, from simple forms to X-rays, likewise motivates companies to get their storage houses in order as inexpensively as possible without sacrificing utility and reliability.

Virtualization. "Server virtualization is a big driver," says John Sloane, analyst with Info-Tech Research Group. Many midsize companies that may not have invested in network storage because of cost now look to consolidate more of their Windows and x86 architecture with VMware. "To get the best benefit from VMware [for] disaster recovery, high availability and advanced data protection, you're really driven toward putting the virtual-machine files and data on a SAN," he says.

Cases in Point

When VMware added iSCSI support last year, another hurdle to adoption fell away. That means companies that "may have been on the fence about purchasing network storage or staying with direct-attached storage now have a trigger that helps them see networked storage," Sloane says. The confluence of these trends has led Burton Group analyst Nik Simpson to refer to Fiber Channel as "dead technology walking."

Many customers aren't waiting for 10G Ethernet; they're finding plain old Ethernet has more than enough horsepower to get the job done. That's the case for the IT department of Clackamas County, Oregon, which has moved from Fiber Channel to an EqualLogic iSCSI SAN.

"Our Fiber Channel stuff is now completely gone except for one Brocade switch, [which] we bought specifically to manage IBM tape drives," says Chris Fricke, senior IT administrator of information services for the county. "Now, everything is on iSCSI SANs: our normal file storage, our document imaging, our Exchange System and our databases," he says.

"It's considerably cheaper not to have to deal with special cards to get it to work, and we didn't have to train people on new technologies. Our primary business goal is not baby-sitting our storage infrastructure," Fricke adds.

Fricke isn't on 10G Ethernet yet, but he's building his storage network with 10G Ethernet in mind. "We'd made the decision that Fiber Channel wasn't working out and iSCSI was the bomb," he says. "We had to look at the entire market, so we did the evaluation. The biggest driver was cost. With Fiber Channel, what we had was 1GB host bus adapters (HBA), a 1GB backplane. To upgrade all that really is a forklift upgrade to pull it out and bring in four gigs or whatever. For us, that would have been at least a half-million [dollars] and not feasible. So we brought in EqualLogic for $50,000, and we'll grow that as we need it."

"Analysts have been talking about iSCSI on 10-Gigabit Ethernet for three or four years. It's taken awhile, but now it really is gaining traction and coming up the ladder," adds Info-Tech's Sloane.

Scott Christiansen, IT director for Leo A. Daly, an international architecture and engineering firm in Omaha, is also impressed with iSCSI SANs. The advantage of moving from a complete network-attached storage (NAS) environment to an iSCSI vs. a Fiber Channel SAN is cost "first and foremost," he says.

Indeed, Fiber Channel switch-and-HBA combos easily run to Rs 1.6 lakh per unit, whereas standard iSCSI SANs can operate with off-the-shelf cards.

The Daly Show

In Leo A. Daly's case, a Fiber Channel solution would have cost six figures compared with less than half that for an iSCSI solution, Christiansen says.

The cost savings of iSCSI over Fiber Channel happen at every level, from the cabling up through the switch ports on the IP switches, Forrester's Reichman says.

Best Best & Krieger, a Riverside, California, law firm, is making the transition from HP Fiber Channel technology to iStor Networks storage for e-mail archiving. The move to iSCSI was a no-brainer, especially because the Fiber Channel infrastructure was aging. "For us, going from Fiber Channel to iSCSI was an upgrade," says Tim Haynes, senior manager of IT for the 400-person law firm. "We were pretty well maxed out on the Fiber Channel. To grow that would have been very expensive, and it gets even more complex to have a highly available storage system with Fiber," he says.

Overall, iSCSI brought simplification. The use of standard networking gear for storage traffic is a major benefit. "We're a Cisco shop, and we put in a 1GB Ethernet switch, and that's it. If it goes down, it's easy to move to another port on another switch, whereas to have a Fiber Channel switch sitting on the shelf as a failover, or even having one online for redundancy, is very complicated."

The Gem Group, a Lawrence, Massachusetts, business specializing in promotional wares, also moved from Fiber Channel to iSCSI. It was outgrowing its Xiotech Fiber Channel implementation and evaluated Fiber Channel and iSCSI replacements last year. Its requirement for failover quickly ruled out four of the initial eight contenders on cost grounds, says Brian Smith, technology manager for Gem. The four remaining solutions -- from EMC, Xiotech, Compellent Technologies and EqualLogic -- all appeared to be in the same price range. After Gem Group looked at the cost of management, as well as upfront price, however, only Compellent remained.

Going with iSCSI meant that Gem Group, with a small IT staff, could rely on its existing TCP/IP and IP expertise. "Pricing was huge, but also, with just 18 people on the IT staff, we all wear a lot of different hats, and I was the only one who knew Fiber Channel after administering it for four years. It's difficult to manage, and learning it takes time. We're growing our business, putting in a new ERP system, and we don't want the added expense of Fiber Channel expertise," Smith says.

The Case for Fiber Channel

Of course, just as few companies have ripped out mainframes in favor of PC-based servers, enterprises will not forklift out Fiber Channel for iSCSI. "Fiber Channel will be around for a long time to come," says Tony Asaro, analyst for Enterprise Strategy Group. "There's a ton of investment in Fiber Channel in time, money and resources," he says.

Asaro adds that religious and political fiefdoms within companies can prolong a technology's life span. There are storage constituencies within organizations that have bet on Fiber Channel and will defend it to the end.

The result doesn't have to be an all-or-nothing proposition. Scott Winslow, founder and CEO of Winslow Technology Group, a Boston storage specialist, estimates 10 percent to 15 percent of his customers are on iSCSI, 30 percent on Fiber Channel and about 60 percent on a combination.

A common misperception about iSCSI SANs is that they can run on the same Ethernet backbone as other traffic. That is technically true, but the thought of such commingling is anathema to some experts, who cite security concerns.

In reality, the recommended implementation for iSCSI storage is to run it on a separate Ethernet network. Even in that instance, the costs are less than with Fiber Channel, because IT staff is dealing with the same set of protocols and management tools across data and storage backbones.

The Gem Group maintains separate storage and data networks for security and performance reasons "but the switches are interconnected," Smith says. "We have the data center and one data closet, so we have some physical servers and some virtual servers in the secondary closet along with a secondary SAN that's connected at fiber-optic speeds. That let us do longer distances between data sites without degradation," he says.

In addition, although iSCSI on Ethernet runs on standard cards, performance-boosting and pricier HBAs still are often necessary to take advantage of 10G Ethernet. Thus, the real cost savings of moving from Fiber Channel to iSCSI may be less dramatic than some proponents say. Winslow Technology's Winslow estimates in some cases the savings is more like 10 percent to 15 percent than the higher figures some pundits cite.

It seems certain that the cost of Fiber Channel components will fall as iSCSI storage gains ground, further narrowing the price gap. Although purists may not be pleased, a hybrid Fiber-Channel-and-iSCSI approach is finding acceptance in many sites.

Winslow, who sells Compellent products, says several of his customers use Fiber Channel for their main storage repository but plug in additional iSCSI cards for failover storage needs.

Experts agree: iSCSI It Will Be

But even after giving Fiber Channel its due, the consensus is that iSCSI is the ultimate winner.

Analysts and users cite the upfront cost of Fiber Channel components, but stress that specialized expertise continues to be a problem. Winslow agrees that companies adding to an existing storage infrastructure or moving from direct-attached storage, more likely will opt for iSCSI over Fiber Channel. Another iSCSI plus is that such important features as data replication and snapshots have been à la carte menu items in the Fiber Channel realm but are part and parcel of iSCSI.

EqualLogic's storage solution brought Leo A. Daly advanced features, including snapshotting and bit-level replication between devices, for which they would have had to pay extra in the Fiber Channel world, Christiansen says. Snapshotting lets the system roll back to data at a set period in time in case of a failure.

Clackamas County's Fricke also stressed this point: "When we bought Fiber Channel, we couldn't even afford snapshotting or replication." Both capabilities are now deployed at no extra cost.

IT experts also say that with implementation know-how, iSCSI can rival current Fiber Channel speeds.

The Gem Group's Smith opted for HP switches that will support 10G Ethernet if the company needs to go that route, but he also went with enterprise-class connections rather than standard network interface cards to optimize performance.

"We do multiple connections, on each server. I go with a two-port QLogic card with two 1GB connections. You can connect that into the SAN in active/active mode. People say Fiber Channel is faster at two or four gigs, but I already have two gigs with iSCSI," Smith says.

Storage analysts see the writing on the wall. "We believe that iSCSI will be the dominant SAN interconnect over time," the Enterprise Strategy Group's Asaro says. "Although Fiber Channel is the leading storage-networking interconnect, it is not ubiquitous because ultimately, it is expensive and complex." Companies that have implemented it see the value in terms of performance and reliability.

"However, Fiber Channel has not reached universal adoption and therefore requires either complementary or replacement technology. This is where iSCSI plays a vital role," he says.

Sloane of Info-Tech agrees. "There is tremendous growth opportunity. For iSCSI there is nowhere to go but up."

This story, "Fiber channel's funeral march" was originally published by CIO.


Copyright © 2008 IDG Communications, Inc.

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