Revo RU8NVR2AX User Manual page 138

NOTE!
Before you begin, ensure that the NVR is connected to a fully functional
DNS server (configured under System > Network).
The time that a cloud upgrade takes is affected by network connection
status.
Local upgrade

Select the directory where the upgrade file is, click Upgrade to start
upgrade.
Camera Upgrade
Click Check to see if the version of the connected IP camera is up to date.
You may upgrade cameras by cloud (
select multiple cameras and then click Upgrade by Cloud or Upgrade By
Disk to upgrade cameras in batches.
) or by disk (
138
) one by one, or