It became clear, about a year ago, to California's County of Orange Integrated Waste Management Department (IWMD)...
that its backup process would need to be upgraded. Backups and restores from tape were taking too long for the company to keep up with tracking incoming waste tonnage and provide billing information to haulers. But the company soon found that to get the data replication it wanted, it would also have to replace its SAN vendor, Xiotech Corp.
"We absolutely loved Xiotech -- in the beginning," said Patrick A. Copland, senior technical systems specialist for IWMD. "They were a terrific, ambitious company with a pioneering product."
Copland said IWMD stored its data on Xiotech's first-generation product, the Magnitude SAN array, which is now differentiated from its newest product, the Magnitude 3D, with the label "Magnitude Classic." The cabinet was a 32-drive Fibre Channel (FC) SAN with eight connectivity ports on the backplane.
But when the product was finally demonstrated for them, Copland said, "We saw no benefit over the older Magnitude, except that the 3D now had dual controllers and had its drive bays separate from the controller. We were looking for asynchronous replication, snapshots, and policy-based data migration."
Eventually, he said, Xiotech partnered with other companies to add replication and snapshot capabilities to its boxes, which Copland dismissed as "second rate. Especially the Timescale replication -- we would've had to devote a T3 connection to it, and it would've cost $100,000 per link. They had another replication option that would've required a NAS head, and we weren't interested in NAS." Copland said IWMD values block-level access to data because the goal was to boot its servers off the SAN.
Xiotech did add more lower cost options to its replication product line, including the TimeScale 100, targeted for the midmarket, but Copland didn't stick around to wait for them. Instead, he said, he started looking for another SAN vendor that would allow him to do snapshots and replication natively, allow him to connect both FC and iSCSI to the same box, and do a SAN boot.
Two companies stood out in his search: EqualLogic Inc. and Compellent. He liked EqualLogic's replication and snapshotting capabilities, but getting FC and iSCSI in the same box required an FCIP converter, which would be expensive. Compellent's system, he said, uses a QLogic Corp. iSCSI card on the front end, which is less costly than an FCIP converter.
"It is true that we would have to use an FCIP bridge," said John Joseph, vice president of marketing for EqualLogic. "But we believe that cost is offset when you consider that using the QLogic card also requires an FC HBA [host bus adapter], which is also a substantial cost."
Joseph added that customers concerned about the reliability of their disks might be interested in a SAS offering, which he said EqualLogic "would be announcing very shortly."
"SAS can offer the same performance of FC and work with our replication via TCP/IP," Joseph said.
Today, Copland said, the company has approximately 1 terabyte of data on one Compellent drive chassis, and he said he will probably add another in the next year. The Compellent SAN is connected using redundant T1 connections to a disaster recovery site, which he said cost roughly $3,000 per asynchronous replication link. While he's currently using all FC disks within the array, Copland said he was thinking of adding a chassis of SATA disks for secondary storage.
As for the drawbacks to using Compellent, Copland cited "the newness of the company. It's something we're willing to take a risk on, as we were with Xiotech, but we were more wary this time. We wait until everything is actually released before we agree to try it out. Promises are now just talk to us."
"It should be emphasized that this decision was made at least 12 months ago," said Mike Stolz, vice president of marketing for Xiotech. "Since that time, we've worked hard to add more flexibility to our replication offerings and features to our arrays, including file and volume-level replication, compression and encryption."