failures of IP cams, NVR, HDD failures, cable ???

Friends do we have any alerts like sms or mails on ip cam, NVR, HDD failures???

Theft happened in my street. They damaged cams, cut the cables....

There are a couple of ways of doing this, depending on what you're running.

Some NVRs or PC based NVR software will send alerts on signal loss or network loss. Likewise, many cams will send alerts if the image is blocked or on network loss. Of course, if you lose the network or if they cut the cable supplying power, cam-based systems won't help.

Another approach is to have the NVR or PC monitor the IP addresses of the cameras and send out alerts if they go offline. You could set up a script in either Windows or *nix to ping the cameras on a regular basis and run the appropriate action if something goes wrong.

My Windows NVR, running Blue Iris, runs a script that pings the POE switch and checks that BI hasn't locked up, and reboots if either loses contact for more than a certain length of time. It would be easy to add pings to all the cameras. In theory, you could do this on any *nix based dedicated NVR, but I don't know those systems well.

It is also good practice to have over lapping camera views, so one camera is almost looking at another camera's area.

Hikvision NVRs can detect when a camera is lost and will save the previous time period before it happened, that might catch when the person destroyed the camera.