Normally, when the HDD is full, the NVR will stop recording new videos to the HDD, but you can set the NVR to overwrite the old files when the HDD is full. Check the detailed information below.

Applies to: Reolink NVRs 

Refer to the guide below about how to turn on the overwrite function.

How to Set the HDD to Overwrite Old Files

If you want to expand the capacity of the HDD, check below.

How to Expand the Capacity of Reolink NVRs.