Does Linux support SMB transparent failover in HA NAS clusters?
Applicable Products
QuTS hero h5.3.0 or later
Answer
No. When a failover occurs in a high-availability (HA) cluster of QNAP NAS devices, any ongoing SMB file transfers between the cluster and a Linux client will be interrupted and will not resume after the failover. You must reinitiate the file transfer manually.
Details
QNAP HA clusters support SMB transparent failover with Persistent Handles. However, the feature currently only works with Windows clients.
Persistent Handle—also known as Durable Handle v2 or DH2C—is a feature introduced by Microsoft that allows file operations to automatically resume after a temporary SMB connection drop. This helps improve connection reliability and data consistency.
However, the SMB client implementation in Linux (maintained by the Samba project) has not yet added support for DH2C. Even if the Samba server (in this case, a QNAP NAS device) supports DH2C, Linux clients accessing shared folders on the server will not be able to automatically recover interrupted file operations.
Further Reading
Does macOS support SMB transparent failover in HA NAS clusters?
