DNAS Backup from Snapshot of Nutanix file shares are failing with "An existing snapshot is no longer valid or cannot be mounted for subsequent operations"

Problem

DNAS Backup from Snapshot of Nutanix file shares are failing with "An existing snapshot is no longer valid or cannot be mounted for subsequent operations"

Error Message

Error in job details:
Dec 13, 2021 10:34:49 AM - Info bphdb (pid=99860) done. status: 1542: An existing snapshot is no longer valid or cannot be mounted for subsequent operations
Dec 13, 2021 10:34:49 AM - end writing
Operation Status: 1542

bppfi log from Backup Host:
11:10:24.582 [13556.16120] <4> log_to_bppfi: [return_smb_export_snapshot_unc_path]: Checking if device [\\<ip>\jontest\.snapshot\<snapshot_name>\] is accessible.
11:10:24.629 [13556.16120] <4> ProcessContext: ProcessName:[bpfis], FipsMode:[DISABLED], Username:[<username_here>], IsServiceAdmin:[0]
11:10:24.629 [13556.16120] <4> log_to_bppfi: [return_smb_export_snapshot_unc_path]: Error: Exported snapshot is not accessible.
11:10:24.629 [13556.16120] <4> ProcessContext: ProcessName:[bpfis], FipsMode:[DISABLED], Username:[<username_here>], IsServiceAdmin:[0]
11:10:24.629 [13556.16120] <4> log_to_bppfi: main_mount_frag: Error: Exported snapshot smb paths are not accessible.

Cause

The <username> listed in the logs does not have access to the exported snapshot.

Solution

Per documentation:
https://www.veritas.com/content/support/en_US/doc/155729295-159316248-0/v157118921-159316248

1. Log on to the prism console.
2. Open the file servers list, and click the file server where you want to create your SMB shares.
3. Select User Mapping in the Protocol Management link in the right corner.
4. Click Next multiple times, till the Explicit Mapping dialog appears.
5. Click Add One to One Mapping and add your domain user and add NFS ID, save and click Next.
You must add one domain user to the default mapping. Save the details.

6. Click Manage Roles in right pane for selected file server.
7. Add your domain user in the Add Admins section and select Role as Backup admin: Backup access only.
8. Save and close the dialog.