The backup scenario comprises of file servers in branch offices all over Germany, which are backed up to NAS units at each location utilising Arcserve D2D.
The backup strategy is "Incremental for ever" and comprises a single full and 31 incremental backups. As soon as the 31 incremental backups have been exceeded, the oldest version is automatically integrated into the full backup and removed from the storage space. This task runs automatically after the backup and catalogue creation has completed and ensures a full backup with 31 days incremental changes for each server. Recovery of lost files and folders can be carried out remotely, recovering the data from the local NAS rather than transmitting data across the WAN.
Arcserve RHA is used to replicate changed files on the NAS to a replicate copy in the customers datacenter utilising SANs to provide the amount of storage space required. In the event of a branch server and/or NAS being lost to fire, water damage or even theft, a bare-metal-recovery would still be possible by means of the Replicate server copy in the datacenter - even if the replacement hardware is different from the original specification. The bandwidth for the replication service can be defined in the Arcserve RHA settings so as not to cause network issues during business hours.
The virtualized replica servers are backed up in turn to virtual and physical tape libraries using Arcserve Backup and are deduplicated at the backup target to save space. Arcserve D2D is now being replaced with Arcserve UDP, and I expect that a migration to UDP will follow within the next 12-18 months. UDP builds upon the D2D concept and source code, but also includes a number of bug-fixes and new functions such as De-duplication at source - if this function works as well as Arcserve claims, this will radically reduce the amount of data replicated across the LAN/WAN environment.