Agencies seeking oomph for their storage area networks can consider a pair of emerging technologies: 8 gigabit-per-second Fibre Channel and iSCSI.
Fibre Channel remains the gold standard for SANs, thanks to its reliability and fault tolerance. Consolidation, virtualization, blade servers and multicore CPUs are all driving demand for the 8Gbps version of the technology, notes Tom Hammond-Doel, vice chairman of the Fibre Channel Industry Association.
For example, if a data center consolidates 20 servers, it boosts the need for aggregate bandwidth and input/output operations per second (IOPS). “Let’s say we put eight virtual machines on one physical machine. With 8G Fibre Channel, each has essentially a 1Gbps pipe to the outside world,” Hammond-Doel says. “We’re finding that 8Gbps Fibre Channel is a perfect play into the virtualization market.”
Late last year, 8Gbps switches arrived on the scene from manufacturers such as Brocade, Cisco Systems, Hewlett-Packard and QLogic; Brocade, Emulex and QLogic offer 8Gbps host bus adapters (HBAs).
Federal agencies are among the early adopters, “particularly in the larger data centers and large-scale computing environments that are moving more data,” says Greg Schulz, founder and senior analyst for StorageIO and author of The Green and Virtual Data Center.
Not all organizations need the speed of 8Gbps Fibre Channel yet. But video-streaming applications such as surveillance and video editing can benefit, as can environments in need of overhead capacity, says Richard Rose, product manager for Cisco’s Data Center Switching Technology Group.
Plus, there’s a piece missing for many data centers, he says: 8Gbps Fibre Channel disk and tape arrays. “As soon as there are 8Gbps targets, backups will benefit,” Rose says.
iSCSI Deployment Advances
High-speed Ethernet has helped spur iSCSI deployment. Running iSCSI traffic over Ethernet offers a low-cost alternative to Fibre Channel. “Typically, when you think of 10Gbps or 1Gbps SANs, you’re thinking iSCSI,” says Rose.
Agencies focused on reducing costs may choose iSCSI to consolidate data and storage networks, Schulz notes. Manufacturers such as FalconStor, Fujitsu, iStor Networks and LeftHand Networks, among others, provide 10Gbps iSCSI SAN switches. iSCSI networks don’t require HBAs, allowing agencies to use network interface cards.
An additional iSCSI appeal is that it’s easier to support. Workers can use existing Ethernet knowledge rather than having to acquire the more specialized Fibre Channel skill set. Plus, some FIPS-certified 8Gbps Fibre Channel gear can perform link level encryption between any two ports to protect traffic between switches.
So far, “95 percent of iSCSI deployment is done on 1Gbps Ethernet,” Schulz says. The reason for that is cost. A 10Gbps Ethernet adapter costs around $1,000. “Moving forward, we’ll see more 10Gbps iSCSI adoption,” he predicts.
The Surface Combat Systems Center’s 200 terabyte SAN configuration uses both Fibre Channel and iSCSI technologies, says Les Martin, tactical systems engineer at the Wallops Island, Va., Naval facility. “Our SANs are dual-hatted,” he says. “We use the right principle: iSCSI is right for the right application and environment, as is Fibre Channel.”
The full-duplex bandwidth that an 8G Fibre Channel module with 48 auto-sensing 1/2/4/8-Gbps ports can deliver.
Though he can’t go into the particulars, Martin says the Surface Combat Systems Center possesses a unique application of storage technology. “The systems that we connect the SANs to are shipboard weapons systems. We replicate multiple configurations for 84 different warships in an environment as close to a ship as possible, without burning fuel.”
The SAN rollout is part of the 10-year roadmap for the Program Executive Office for Integrated Warfare Systems’ SANs Across America initiative. Wallops Island’s SAN configurations run 4Gbps Fibre Channel, but its SAN gear is capable of 8Gbps Fibre Channel. “Fibre Channel is the de facto protocol for transporting data now,” Martin says.
Cisco’s Rose recommends planning for the future by choosing a Fibre Channel switch that’s 8Gbps-capable, then picking and choosing a mix of pluggable optics. 8Gbps optics currently run three to four times the price of 4Gbps. “You’re paying a 20 to 30 percent premium at a solution level,” he says.
With time, though, the price premium will drop. Schulz notes Hewlett-Packard offers a four-server, 8Gbps SAN starter kit for about $8,000, which is less expensive per port than 10Gbps Ethernet.
Schulz expects that agencies will start jumping on 8Gbps Fibre Channel this year, with the big push happening in 2010 and 2011. After that, “in three or four years, 16Gbps Fibre Channel may be out by then, or users may make the transition over to Fibre over Ethernet (see below).