The ExaGrid disk backup appliance uses post-processing to perform its deduplication. This means that the backup data is written directly from the backup server to ExaGrid's Landing Zone (disk) at the highest possible rate with no inline processing to interfere, resulting in the smallest possible backup window. Once the backup job is complete and off the network, the data is protected and immediately available for restore or tape copy. Then the appliance deduplicates (and simultaneously replicates) the data in the background. Because ExaGrid's product allows each full backup to first land to the landing zone, it caches that most recent backup for rapid restore. Since over 90% of restores are done from the most recent backup, this approach avoids overhead incurred of undoing any deduplication during critical restores.
Once virtualized, they appear as a single pool of long-term capacity. Capacity load balancing of all data across servers is automatic, and multiple GRID systems can be combined for additional capacity. Even though data is load-balanced, deduplication occurs across the systems so that data migration does not cause a loss of effectiveness in deduplication.
