Camera footage is the foundation of every system, yet there is more than one way to store it. When is an on-site recorder sufficient, when does off-site backup become worthwhile, and how much storage space should actually be calculated?
An NVR (network video recorder) is a device that stores footage from all cameras directly on-site, in your warehouse, office or home. The advantage is quick access to recordings even without an internet connection and the fact that data remains physically with you. The disadvantage is vulnerability to theft or damage: if someone takes both the cameras and the recorder, the recordings disappear with them. Therefore, in more sensitive operations, the recorder is placed out of reach and outside the camera view, ideally in a locked room.
In addition to the recorder, the recording, or at least its essential part, can be stored off-site with the service provider. The advantage is clear: the recording survives theft or destruction of equipment on site and is accessible from anywhere. The disadvantage is usually dependence on a high-quality internet connection and ongoing costs for storage space. In practice, therefore, remote storage most often functions as a supplement to the NVR, not as its replacement, key footage (for example, only from detected events) is backed up off-site, while standard continuous recording remains on the recorder.
Capacity depends on three factors: the number of cameras, their resolution and recording settings. A high-resolution camera recording continuously takes up significantly more space than one with the same resolution that records only upon a detected event. This is why it pays to set systems with AI detection to record "on event" with a short pre-recording buffer: the footage then uses a fraction of the space compared to continuous capture, without losing anything important. We always calculate the exact capacity based on the specific camera setup during the design phase, so the hard drive lasts for the entire intended retention period.
A smaller premises with four cameras and continuous recording typically requires a recorder with several terabytes of storage for a two-week retention period. The same setup recording only on detected events needs significantly less capacity for the same retention time, as hours of empty footage from a quiet courtyard or an empty corridor are not stored. The exact figure always varies depending on resolution and the amount of movement in the frame, but this ratio is why event-based recording has practically become the default choice for new installations.
Recorders and cameras require power, in the event of a power outage without a backup source, recording is lost completely for minutes or hours, typically at the worst possible moment. In operations where this matters, it pays to equip the recorder and key cameras with a backup power supply that bridges short outages and ensures the system shuts down correctly even during longer ones. It is an inexpensive safeguard against the premises being left unmonitored precisely during a power cut.
As a general rule, recordings should be retained only for as long as necessary. That is, just long enough to address any potential incident, and no longer. In practice, for most premises and businesses this typically amounts to one to two weeks, and in lower-risk areas it can be even less. We deliberately choose a longer retention period only where justified, such as at entrances with number plate recognition, where access to recordings may sometimes occur after some time has passed. The retention period is set as part of the installation, along with defining who has access to the recordings, more on this in the article about cameras and GDPR in practice.
Both the recorder and the discs are devices like any other and wear out over time, especially during continuous operation. It is therefore worthwhile to have regular servicing arranged, which checks the condition of the equipment before the disc actually fails and recording stops without warning. For the systems we supply, ongoing servicing and checking the status of the recorder are standard parts of care, not just a reaction to a reported fault.
The recording itself will only tell you what happened once you review it. However, combined with AI detection, the system automatically recognises when something occurs and alerts you in real time, allowing you to quickly locate a specific event by description in the stored footage, rather than scrubbing through hours of video. A complete overview of what such a system includes can be found on the page Camera system with recording for businesses.
Free design of a recording solution based on the number of cameras and the retention period you require.