The recording vanished when you needed it: 6 common causes and how to avoid them

You need footage of an incident from two weeks ago, you open the recorder, and the video is not there. This story keeps repeating, and it is not luck; it has known causes. Here are six ways recordings get lost, and how to make sure the footage is there when you need it.

1. The disk filled up and started overwriting old footage

If the capacity was never calculated, the system deletes the oldest footage automatically. The quote that said "a month of recording" may in reality give you a week. Ask for the retention calculation in writing, and test it after commissioning by checking the oldest recording available.

2. A memory card instead of a recorder

Some cheap cameras record to a small card. Ordinary cards fail quickly under continuous writing, and if the camera is stolen the recording goes with it. For serious systems, recording should be on a central recorder with disks made for surveillance, in a protected place.

3. An expired cloud subscription

Some cameras depend on a subscription cloud service: when the subscription ends or the company stops operating, access and recordings disappear. Ask before you buy: where is the video stored? What happens if the service stops? Do I keep a local recording?

4. A power cut with no UPS

The power goes off for a few seconds, the recorder shuts down improperly, and sometimes the disk is damaged or the file is corrupted. A small UPS on the recorder and the switch protects you and gives time for a proper shutdown. And a recorder that is down for hours recorded nothing in that period.

5. The wrong time and date

A clip whose time differs from the real time loses its value when someone needs it. Set time synchronization with a time server, and check the clock at every maintenance visit.

6. Nobody monitors the system

A disk failed months ago and the system told no one, or a camera's angle shifted, or a lens got covered in dust. A good system sends an alert when a disk fails or a camera is lost, and has a periodic visit.

How do you make sure the recording is there?

• Calculate capacity on the actual night bitrate, and add a margin.
• Record to a central recorder, not to a card inside the camera.
• Put the recorder and the switch on a UPS.
• Enable alerts for disk failure and camera loss.
• Once a month: retrieve an old recording and confirm it is clear and its time is correct.

A surveillance system that is never tested is like a fire extinguisher that is never inspected: you assume it works until you need it.

Frequently asked questions

How much hard drive capacity is enough for eight cameras?

It depends on resolution, the actual bitrate, retention days and the recording mode. Use the storage calculator on the CCTV page, and measure the bitrate at your site instead of relying on the datasheet figure.

Is a memory card enough for recording?

Only for light use or as a backup. For serious systems we recommend a central recorder with disks suited to surveillance, placed in a protected location.

Do I need a UPS for the recorder?

Yes, it is recommended: a sudden power cut can damage the disk or the files, and the UPS gives time for a proper shutdown and keeps recording through short outages.

How do I check that the system is actually recording?

Test it monthly: find an old recording from each camera and confirm it is clear and its time is correct. And enable alerts for disk failure and camera loss.