What is MercuryFTP?
Question
What is MercuryFTP?
Environment
- Datto Windows Agent
- Datto Linux Agent
Answer
MercuryFTP is the primary transport method for the Datto Linux Agent and Version 2.0 and above of the Datto Windows Agent. Older versions of the agent software use iSCSI only.
MercuryFTP is a custom data transfer protocol created by Datto specifically for backing up Windows-based production machines. It can perform compression and encryption, and acts as a windowed protocol that allows writing of a second block of data before the first one has finished. Mercury FTP uses TCP port 3262 to communicate with the protected system.
MercuryFTP also increases the efficiency of the differential merge process. To perform a differential merge, the iSCSI and Samba transport methods must read a block from a Datto appliance, compare it to what exists on the production machine, and update the backup set if it is different.
Unlike iSCSI and Samba, MercuryFTP queries the server on the Datto appliance for the hash of the block, which is much shorter to send over the network. Only if the hash doesn't match will the device then send the block. This process creates far less I/O for the same outcome.
