DIF stands for Data Integrity Field. The purpose of this field is to provide End-to-End data protection in Computer/Enterprise data storage methodology.
Data integrity concerns are not new, and protection mechanisms abound. Packet-based storage transport protocols have CRC protection on command and data payloads. Interconnect buses have parity protection. Memory systems have parity detection/correction schemes. I/O protocol controllers at the transport/interconnect boundaries have internal data path protection.
Data availability in storage systems is frequently measured simply in terms of the reliability of the hardware components and the effects of redundant hardware. But the reliability of the software, its ability to detect errors, and its ability to correctly report or apply corrective actions to a failure have a significant bearing on the overall storage system availability.
The data exchange usually takes place between the Host/CPU and Storage disk. There may be a storage data controller in between these two. The controller could be RAID controller or simple storage switches.