I have a Dahua NVR 5216-4KS2 with 1x4TB HDD working well with 4 IP cameras. Running well for a year.
I'm planning to add more cameras, so decided to add another HDD (exact same make and model WD Purple).
a) Initially, with the added 2nd HDD, the NVR booted up and run well. Could see...
Present the Dahua Pro NVR 2 Disk 16CH 16PoE+ 4KS2 (5216-16P-4KS2)
Initial Impressions: I'm directly comparing this to my experience w/a 4216-4K.. I have 10 Channels of 2MP-4MP cameras on H264 & H265 connected via external PoE, I will not be using any of the internal PoE ports on this.