SMB Remote File Protocol (Including SMB 3.x) (February 2015)

The SMB protocol evolved over time from CIFS to SMB1 to SMB2, with implementations by dozens of vendors including most major Operating Systems and NAS solutions. The SMB 3.0 protocol had its first commercial implementations by Microsoft, NetApp and EMC by the end of 2012, and many other implementations exist or are in-progress. The SMB3 protocol continues to advance. This SNIA Tutorial describes the basic architecture of the SMB protocol and basic operations, including connecting to a share, negotiating a dialect, executing operations and disconnecting from a share. The second part of the tutorial covers improvements in the version 2 of the protocol, including a reduced command set, support for asynchronous operations, compounding of operations, durable and resilient file handles, file leasing and large MTU support. The final part covers the latest changes in SMB3, including persistent handles (SMB Transparent Failover), active/active clusters (SMB Scale-Out), multiple connections per sessions (SMB Multichannel), support for RDMA protocols (SMB Direct), snapshot-based backups (VSS for Remote File Shares) opportunistic locking of folders (SMB Directory Leasing), and SMB encryption.