Something happens at your shop or office: a missing delivery, a dispute with a customer, a damaged car in the parking. You open the CCTV app to check the footage, and the recording only goes back a few days. The event you need has already been overwritten.
This is one of the most common CCTV problems we see in the UAE. The cameras work fine, but the recorder was never sized for the number of days the business actually needs. Here is how recording days work, what affects them, and how to plan storage properly.
How CCTV recording actually works
Your cameras send video to a recorder, usually an NVR (network video recorder) for IP cameras. The NVR saves the video onto hard drives inside it. When the drives are full, the NVR deletes the oldest footage and keeps recording. This is called overwrite, and it is normally switched on so recording never stops.
So the number of days you can look back is simply: how much the drives can hold, divided by how much video your cameras produce each day. More cameras, sharper pictures or busier scenes use space faster. Bigger or more drives give you more days.
First, decide how many days you need
Before talking about hard drives, ask a simple business question: how long after an incident do people usually notice it?
- Shops and restaurants: cash or stock issues are often noticed at the weekly or monthly stock check, so a few days is rarely enough.
- Offices: disputes, missing items or access questions may come up weeks later, sometimes after a staff member has left.
- Warehouses and logistics: a damaged or short shipment may only be reported when the customer receives it, which can be a long time after dispatch.
- Villas and homes: if you travel in summer, you want footage covering the whole time you are away.
Many UAE businesses also fall under the rules of SIRA (the Security Industry Regulatory Agency in Dubai) or the relevant authority in other emirates, which set requirements for camera systems and how long footage must be kept for certain activities. Requirements differ by business type and can change, so check the current rules for your activity before you buy. A good installer will ask about this during the site survey.
What uses up storage
Two systems with the same number of cameras can need very different storage. These are the main factors:
- Number of cameras. Each camera adds its own daily amount of video.
- Resolution. A 4MP or 8MP (4K) camera produces much more data than a 2MP camera, especially at full quality.
- Video compression. Newer formats such as H.265 and the "smart" versions offered by most brands store the same picture in noticeably less space than older H.264.
- Frame rate. Recording at a lower frame rate saves space. For general monitoring, a moderate frame rate is usually enough; cash counters or entrances may deserve more.
- Scene activity. A busy shop floor or road uses more space than a quiet corridor, because more of the picture changes.
- Night and colour. Colour night cameras and noisy low-light scenes can increase the amount of data at night.
- Continuous or motion recording. Recording only when something moves can stretch storage a lot in quiet areas.
A simple way to estimate storage
Every camera stream has a bitrate, measured in Mbps (megabits per second). You can see it in the NVR or camera settings. The rough calculation is:
Bitrate (Mbps) ÷ 8 × 86,400 seconds = megabytes per camera per day
For example, a camera recording continuously at 4 Mbps produces about 0.5 MB every second, which is roughly 43 GB per day. Multiply by the number of cameras and the number of days you want, and you have the storage you need.
| Example (continuous recording, 4 Mbps per camera) | Per day | For 30 days |
|---|---|---|
| 1 camera | about 43 GB | about 1.3 TB |
| 8 cameras | about 350 GB | about 10.4 TB |
| 16 cameras | about 690 GB | about 20.7 TB |
This is only an illustration. Your real bitrate depends on the camera model, settings and scene, so the best approach is to set up the cameras, check the actual bitrate, and size the drives from that. Always leave some spare space rather than sizing exactly to the limit.
Ways to keep footage longer without replacing everything
- Add or upgrade hard drives. Many NVRs have empty drive bays or support larger drives. Check the NVR's supported capacity first.
- Switch to H.265 or smart compression if your cameras and NVR support it.
- Use motion or event recording for quiet areas such as stores, corridors and back doors, and keep continuous recording for entrances and cash points.
- Adjust frame rate and quality per camera. Not every camera needs maximum settings.
- Use a sub-stream for less important cameras, if your system supports recording at lower quality.
- Back up important clips straight away. If something happens, export the footage to a USB drive or secure storage the same day, before it is overwritten.
Use the right hard drives
CCTV recorders write video 24 hours a day, every day. Normal desktop drives are not designed for this and tend to fail early. Use surveillance-rated hard drives made for constant recording. In a hot environment like a UAE server cupboard or shop back room, keep the NVR ventilated and away from direct heat, because heat shortens drive life.
Also remember that a hard drive can fail quietly. The NVR may keep showing live video while nothing is being saved. That is why regular checks matter.
Check your recording regularly
Do not wait for an incident to find out what you have. Once a month, open the playback and check:
- How far back the oldest recording goes, for each camera.
- That every camera is recording, not just showing live video.
- That the NVR shows no hard drive errors or warnings.
- That the date and time on the NVR are correct, so footage is useful as evidence.
If you have an annual maintenance contract, these checks should be part of every visit.
Need help?
If you are not sure how many days your system really keeps, or you are planning a new installation, SNTECH can check your current recorder, calculate the storage you need and recommend the right drives and settings. See our CCTV installation in Dubai page, our Hikvision CCTV page, or ask about a CCTV AMC and repair plan so your recording is checked regularly. We work across Dubai, Sharjah, Ajman, Abu Dhabi, Ras Al Khaimah, Umm Al Quwain and Fujairah.