Persistent file handles facilitate continuous availability (CA) for SMB shares.
During the disruption of service, SMB shares remain continuously available by using the persistent file handles and the high-availability features. Persistent file handles reduce the period of data unavailability by automatically reconnecting users to the file service in-use before the disruption.
Files store open lock information on persistent volume groups available for every FSVM in the cluster. During a fail-over, the fail-over FSVM can access the volume group. Persistent file handles let clients wait to reconnect without notifying the user about the connection failure. As a result, disruptions are seamless to users and applications.
During a lock protection interval, Files does not prevent NFs clients from accessing the file. Files only prevent SMB clients from accessing files during the disconnected state. The periodic handler cleans up stale locks for the disconnected persistent file handles every 24 hours. Synchronous writes on CA shares may impact performance. Nutanix recommends continuous availability for shares with less metadata and more I/O intensive workloads, such as VHD or VHDx based profile disks, where performance impact is minimal.
Enabling Continuous Availability
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To confirm the status of continuous availability, replace the share-name and check the share profile
nutanix@fsvm$ afs share.list sharename=share-name
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Replace the share-name and enable continuous availability on the share
nutanix@fsvm$afs share.edit share-name continous_availability=true