Serverless backup can also remove the media server from the architecture: The master backup server sends a list of files or records across the LAN to the backup client. The backup client translates the list into block addresses and sends the block addresses to a SAN device that supports the SCSI extended-copy (XCOPY) command (also known as “third-party copy”). This SAN device can be an intelligent FC switch platform, an FC router, or a FC-SCSI bridge. This type of device is sometimes referred to as a “data mover.” The SAN device then initiates a direct copy of the disk blocks to tape.
Several SCSI-FC routers implement XCOPY, but this limits the application of serverless backup to legacy SCSI tape libraries that are bridged to the SAN. Because there are limited serverless backup solutions for native FC tape devices, serverless backup has not been widely implemented.