Below are the steps necessary to increase the NVBU Server-side timeout for SmartDisk connections:
1.) Open the NetVault Server's Configurator and go to "Media Manager" and then the "DAV RAS Device Configuration" sub-tab.
2.) Increase the value for "Data transfer stall timeout (seconds)" from the default of 60 to '300' for a 5 minute wait for slow SmartDisk storage, such as iSCSI-attached disks.
3.) From the "Service" tab, stop and start the NetVault service to push time timeout increase live.