iSCSI Tackles DR

Disaster recovery over long distances is the latest target for IP SANs

May 19, 2005

3 Min Read
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iSCSI SANs are capturing the attention of small- and medium-sized enterprises that are sick of tape vaulting and can't afford Fibre Channel for long-distance disaster recovery.

iSCSI gear faces a speed standoff with 4-Gbit/s Fibre Channel, which is causing many to focus on software enhancements (see IP SANs Take Softer Way). But a growing number of suppliers see replication and other facilities for long-distance disaster recovery as key to distinguishing their value. They say smaller customers are more concerned with cost than speed when it comes to DR.

"Just because a company is small doesn't mean it doesn't want to protect its data," says Thomas Isakovich, CEO of Nimbus Data Systems Inc., which makes IP SANs. Nimbus is specifically targeting disaster recovery as a key market.

Isakovich says lots of firms don't want to shell out thousands for special routers to convert Fibre Channel to IP and back again to go over long-distance links. At the same time, they're starting to mistrust old-fashioned tape vaulting (see A Tale of Lost Tapes).

Nimbus today unveiled an Offsite Replicator facility that runs with its IP SAN (see Nimbus Releases Replicator). The product adds about $2,500 to the cost of the array and is specifically aimed at promoting asynchronous disaster recovery for small companies.Nimbus charges "less than $30,000" for a complete IP SAN for disaster recovery, including 1.6 Tbyte of capacity, software, and three years of suppport. Isakovich says the SAN enables users to deploy standard Internet links for disaster recovery, without buying HBAs, new switches, or FCIP gear.

There is a downside: Isakovich acknowledges there's latency over IP storage networks at distances over 200 km, and to solve the problem he's aiming to partner with WAN optimization vendors within the next several months. He mentions no names.

WAN optimizers, which tweak repetitive patterns in TCP transmissions, have also hit the headlines recently, since the acquisition of Peribit Networks Inc. by Juniper Networks Inc. (Nasdaq: JNPR). (See Cisco Prowling WAN Optimization? and Peribit Deal: More to Come.)

The addition of WAN optimizers could add to the cost of IP SANs, perhaps by many thousands of dollars. That said, partnerships could help. And in comparison, the cost of Fibre Channel over IP often requires the addition of even more SAN gear, including routers, switches, HBAs, and software. Also, if tapes are lost in transit, costs greater than these can result.

Other iSCSI SAN vendors also see a chance to pitch disaster recovery and replication as part of their value proposition compared with Fibre Channel. And several, including LeftHand Networks Inc. and FalconStor Software Inc. (Nasdaq: FALC), claim their remote replication techniques obviate the distance issue.Falconstor says its IPStor Enterprise Edition software, which includes remote replication, has been adopted by an Australian Catholic Education Office with multiple sites for its simplicity compared with Fibre Channel (see Falconstor Does iSCSI in School).

EqualLogic Inc., Intransa Inc., and Maranti Networks Inc. also have replication. And replication is one of the reasons University of California at Berkeley is using a Sanrad Inc. IP SAN, according to a release today (see Sanrad Works With Berkeley).

While remote replication and disaster recovery have been part of the iSCSI rationale for awhile, increased competition is likely to sharpen the focus.

Mary Jander, Site Editor, Byte and Switch

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