Is it possible to have about 4 PoE cameras attached to a PoE switch in a network closet which will be trunked to a L3 switch where the NVR will be also attached too?
Or would it be better practice to home the NVR in the network closet to supply the power natively.
Looking at the diagram, I don’t see any issue with the network topology. And the power arrangement also shouldn’t be a problem, unless you require the camera/DVR setup to persist during a power cut.
In that scenario, you would have to provide UPS power to all of: the PoE switch, the L3 switch, and the NVR. But if you don’t have such a requirement, then I don’t see a problem here.