By Kevin Komiega
IBM last month rolled out the fourth version of its flagship storage virtualization platform. The System Storage SAN Volume Controller (SVC) 4.1 has a variety of new features, including support for 4Gbps Fibre Channel SAN fabrics, additional support for storage platforms from other vendors, and the ability to move data over longer distances using asynchronous remote replication. The SVC is a rack-mounted appliance that sits on the network and connects storage systems to host machines and creates a virtual pool of managed disks. The virtualized environment created by the SVC provides for more-efficient storage management and provisioning, according to IBM officials and becomes a common platform for advanced functions such as replication.
The SVC was previously limited to the synchronous replication capabilities of a feature called Metro Mirror, which capped the appliance’s ability to move data efficiently at distances of about 100 miles. IBM officials now say they have married Metro Mirror with a new application called Global Mirror to overcome distance limitations. The Global Mirror feature of SVC 4.1 provides long-distance asynchronous remote replication for business continuity and disaster-recovery purposes. With SVC 4.1, Metro Mirror and Global Mirror are delivered as a single feature at no additional licensing fee for existing Metro Mirror users.
“The most important new function of the SVC is Global Mirror. It is built on the existing base code of Metro Mirror and can move data asynchronously over practically unlimited distances,” says Chris Saul, IBM’s marketing manager for SVC.
IBM’s replication service also allows customers to mix-and-match arrays between primary and secondary sites. To that end, IBM supports a variety of new storage arrays in SVC 4.1, including systems from Hewlett-Packard, Hitachi Data Systems, and Network Appliance.
IBM also added support for 4Gbps Fibre Channel SAN fabrics in the new SVC engines. Existing customers can upgrade their SVC appliances to support 4Gbps Fibre Channel, and 4Gbps nodes can be intermixed in clusters with 2Gbps nodes.
The company also introduced a new approach for upgrading SVC engines in the field. Each SVC appliance is considered a node and the devices are always installed in pairs. Each node in a pair is configured to back up the other. The new Cluster Non-Disruptive Upgrade feature allows customers to replace an SVC with a newer version without disrupting data access.
The SVC 4.1 platform is priced from $42,500.
The replication capabilities in the latest release of the SVC are similar to the technology recently acquired by EMC for its Invista network-based virtualization platform.
EMC acquired start-up Kashya for about $153 million and absorbed the company’s KBX5000 data-protection platform, which features integrated disaster-recovery, replication, and continuous data protection (CDP) functionality.
The major difference between SVC and Invista is their respective approaches to providing advanced services in the network. SVC is a network appliance while Invista’s platform is switch-based and runs on top of Cisco’s MDS family of intelligent fabric switches. But IBM says the biggest difference between the two products is not architectural; it’s product availability.
IBM officials claim that the SVC is the market-share leader in network virtualization platforms, with SVC appliances managing more than 31.6 petabytes of networked storage data in more than 2,000 customer implementations worldwide. IBM also says it is bringing enhanced remote capabilities to customers now while EMC customers will have to wait for EMC to integrate Kashya’s technology into the Invista platform.
“The appliance-based approach fits customer environments because the [SVC] can be easily added to existing fabrics and the entry cost is much lower [than EMC’s Invista],” claims IBM’s Saul.
However, EMC says that pairing its Invista platform with the Kashya technology will have “a substantial technological advantage over anything else on the market,” because the system offers built-in compression that enables high performance over less-expensive, lower-bandwidth WAN links.
One EMC spokesperson says, “We expect our enterprise customers will gladly wait a little longer to get the benefits of high-performance, heterogeneous remote replication functionality and integrated CDP for less cost.”
William Hurley, a senior analyst with the Data Mobility Group research and consulting firm, says that IBM is clearly in the lead, noting that the SVC platform has already gone through several versions and is reliable and highly functional.
However, Tony Asaro, a senior analyst at the Enterprise Strategy Group research and consulting firm, says it is much too soon to declare IBM the winner in the race for virtualization domination. He says IBM may be the current leader in the market, but notes that most potential virtualization users have not yet implemented the technology and are now considering it more seriously because EMC is getting into the game.
“Storage virtualization is still just emerging, so it’s hard to call EMC late because there isn’t a mass market yet,” Asaro says. “The switch versus appliance battle is just beginning.”