Strand Associates is a 380-person firm headquartered in Madison, Wis., with 11 remote office locations. Before buying FalconStor's CDP virtual appliance with continuous data protection (CDP), local and remote replication last September, Strand used a local instance of Symantec Corp.'s Backup Exec data backup software and tape drives attached to local servers at each remote office.
Besides wanting to get rid of tape in remote offices because of reliability and manageability issues (Strand Associates has a total of eight IT staff, but only two outside of Madison headquarters), network administrator Justin Bell said he wanted to get away from the Windows operating system required by Backup Exec. "The Windows operating system requires a substantial amount of patching and maintenance," he said.
EMC's RepliStor software "was cheaper than FalconStor's, but we would've had to purchase additional hardware for the secondary local copy, and we needed quite a few licenses to have the secondary copy at each of the offices." RepliStor, like Backup Exec, is also based on Windows. "It uses [Volume Shadowcopy Services (VSS)], which I've had problems with in the past with large data stores," Bell said.
NetApp's SnapMirror software can perform local and remote replication of, but required proprietary hardware (Bell said he looked at the NetApp FAS2020 system) at the branch office and central data center. Bell said a NetApp salesperson suggested Double-Take for software-based local replication instead, but "we didn't want to have to buy a separate set of software from a different vendor to facilitate it."
The FalconStor device replicates snapshot copies of every write on the production server to a commodity Linux server running FalconStor CDP. The local copies are stored on the server's direct-attached disk and accessed locally through CDP's virtual storage device. Copies of the data are also sent to Madison.
Bell said FalconStor's MicroScan feature was also appealing. MicroScan sends only new data over the wire, and detects changed data at the sector level (512 bytes) rather than the block level. "That shrinks the data enough so it's realistic to replicate it over T1 connections without another WAN optimization product," he said. Further bandwidth throttling features allow him to shut off replication completely during business hours.
So far the product has been protecting data in production since December 2008 with few issues. Right now the company is running CDP 5.1 and in the process up upgrading to CDP 6. "The only downfall we've seen is that it's kind of difficult to upgrade," Bell said. "We have to install a completely new operating system on the appliance, and we can't do it remotely."
Bell also said he'd like MicroScan to work for local as well as remote replication. Now, he said, it looks like the system is recording all data, even if it winds up being replaced with pointers. FalconStor director of marketing Fadi Albatal said MicroScan is available for local replication as well, but has to be turned on as an optional feature. Even when turned on, Albatal said, it can be difficult to see the data reduction as it's happening. "The data looks like it was written, unless you have a separate analyzer of the storage layout," he said.