The Rocky Road to SMB3 Directory Leases (sambaXP 2025)

Talk by Ralph Böhme (SerNet GmbH / Samba Team) at sambaXP 2025. Abstract: SMB3 Directory Leases are a powerful protocol feature that can significantly improve client performance, reduce network traffic, and lower server load by enabling clients to maintain a consistent cache of directory contents. In 2020, I implemented SMB3 Directory Leases as a proof of concept for a customer. At the time, it was clear that further research and rigorous testing were necessary. Now, four years later, Samba 4.22 is set to deliver a production-ready implementation. This talk will explain how Directory Leases work, showcase real-world examples of performance improvements, and reveal how critical bugs in Samba’s existing SMB2 Leases functionality were discovered and fixed along the way. Visit the conference website at: https://sambaxp.org​ sambaXP is organised by SerNet: https://sernet.com