These steps show how to setup a Redundant HDD on Dahua surveillance systems (DVR or NVR) which will keep a copy of the primary drive. In order to do his procedure you need to have at least 2 hard drives on the unit, connected and powered by the motherboard. Also make sure your Dahua recorder supports such feature. Note: this is the not the RAID option, this feature simply makes another copy of the main hard drive.
1. Go to the Main Menu and select Storage.
2. Select HDD manage tab.
3. Click on Read and Write.
4. Select Redundant.
5. Select Apply and Save.
With these settings in place, if your main hard drive goes bad, then you will have the exact hard drive contents copied on the second hard drive. It’s a good option if you’re dealing with very sensitive data and you can’t afford to lose certain video footages.