Overland Storage's new REO Compass appliances take a unique approach to the ROBO (remote office, branch office) backup problem using data deduplication, encryption and compression to replicate backup data to a central site. Unlike Quantum's DXi or Data Domain's appliances, the REO Compass doesn't actually serve as a backup target storing your data but instead replicates data, through a partner, Compass, from one real or virtual tape library to another.The REO Compass is the first solution I've seen that keeps the catalog(s) of your backup application aware of the fact that a second copy of the backup set has been created in a new location. Usually the backup app only knows about the original copy or is confused because it can now see multiple tapes in multiple locations that have bar code label 44532 and the same data.

When you install a Compass, you also install an agent on your backup media sever. Once a backup job you've flagged for replication completes, the agent alerts the Compass appliance, which mounts the tape and sends the data to another Compass. The target Compass mounts a tape, with a different bar code, on a tape library at the other end and saves the data. Once the data's written, the backup agent will use your backup software's CLI (command line interface) to inventory and catalog the new tape. The initial version will support Backup Exec and NetBackup, with CommVault's Simpana and Arcserve to follow.

The REO Compass requires a SAN-attached tape library at each end. The connection can be either iSCSI or Fibre Channel and Compasses will run with most physical or virtual tape libraries, including, of course, Overland's own NEO tape libraries and REO VTLs.

Like the competing appliances, and source deduplicating software like EMC's Avamar, Asigra Televaulting, Robobak or PureDisk, the Compass does global data deduplication, sending hashes of the new tape's data to the target, which then requests the data blocks only for the data it hasn't seen before. Overland said it was very careful to avoid infringing on the Rocksoft patents, so it's not paying license fees to Quantum.

Unfortunately, the Compass doesn't use data deduplication for data storage, so users won't get the disk space savings they would with a DXi or Data Domain. Still, for organizations that already have tape libraries or VTLs in place, the $5,200 for a Compass may well be worth it just to enable backup replication over a reasonable amount of bandwidth.