disk to disk (Backup) (D2D)
Disk to Disk (D2D) is a technology for backups. It involves copying data from a primary hard disk to a secondary hard disk.
The secondary hard disk should be independent of the primary hard disk to ensure data security, so that if the primary hard disk fails, the data is fully available on the secondary hard disk.
Copying from one hard disk to a secondary one is much faster than copying to tape devices. Therefore, D2D technology is recommended as short-term intermediate storage before data is stored on tape drives for long-term archiving. D2D can be used with SCSI as well as in storage networks.