Serverless backup takes the LAN and the server out of the backup data path: In a LAN-free backup, there is no good functional reason for the backup data to flow through the server at all, other than to maintain compatibility with older backup applications which expect to work that way. Meanwhile the high I/O throughput affects server performance. A recent approach is to use the SAN to do direct storage-to-storage copies to implement backups. This frees the server to run applications while backups are running. A server is still required for backup management, but the backup data does not pass through the server.
The SCSI Extended Copy Command, which will make direct storage-to- storage copying much easier, is currently going through approval, and might need some work to reach “industrial strength”. For the time being, some vendors might offer direct storage-to-storage solutions that use proprietary technologies.