Sanrad adds replication to iSCSI switches

Posted on March 01, 2005

By Heidi Biggar

Sanrad this month added network-based remote data replication to the storage services supported by its family of iSCSI-based V-Switches. Existing services include storage pooling, virtualization, mirroring, fail-over, and security.

The company’s V-Switches serve as iSCSI gateways for building IP SANs. Sanrad believes the future of the IP SAN market hinges on the proliferation of medium- to large-scale, not low-end, IP SANs.

Sanrad’s Global Data Replication and Disaster Recovery (GDR) software allows users to replicate data asynchronously or synchronously, depending on bandwidth and latency requirements, between primary and remote data sites in an active-passive, active-active, or star configuration (many primary sites, one secondary site) across a LAN, MAN, or WAN.

Data is replicated at the block, not file, level, which gives users the flexibility to replicate all or select volumes for a faster, less-bandwidth-intensive process. A disaster-recovery journal keeps track of all changes made to the volumes.

GDR is network-based software that runs on V-Switches installed at the primary and remote sites. This is in contrast to host- or array-based replication software (see “Fabric-based replication: new option for BC/DR,” InfoStor, January 2005, p. 24).

Sanrad officials claim that this approach to replication is more manageable and scalable (in part because there are no host agents), more efficient (replication is volume-specific), and more flexible than host-based alternatives and, unlike array-based alternatives, it does not lock users into a specific vendor’s storage arrays. For example, users can replicate from a high-end disk array at a primary data site to a low-cost array at a remote site.

“It’s more efficient than host-based alternatives because there’s less CPU and network load,” says Zophar Sante, vice president of market development at Sanrad. “In addition, there are no per-server or per-volume fees and no host agents.”

A GDR wizard guides users through the replication process, including fail-over and fail-back processes.

Each V-Switch supports up to 256 servers, 54,000 volumes, and 4,000TB. A V-Switch 2000 with GDR software is priced at $19,000, while a V-Switch 3000 with GDR is priced at $32,000.