CCTV Storage — Hard Drives, RAID and Retention

CCTV storage is where most jobs quietly fail months after the install. The cameras work, the network is fine — and then footage from the night that mattered turns out to have been overwritten three days earlier, or a drive failure has corrupted a recorder that nobody was monitoring. This module covers how DVR and NVR storage actually works so installers can specify it correctly the first time.

What this module covers

The lessons walk through hard-drive selection (surveillance-grade vs desktop drives, why WD Purple and Seagate SkyHawk exist), the mechanical and initialisation steps to install a drive into a Hikvision or generic NVR, the difference between continuous and motion-triggered recording, and how to size storage from camera count, resolution, frame rate, codec and required retention. RAID levels — 0, 1, 5, 6 and 10 — are covered with their CCTV implications: when RAID 5 is sufficient, when only RAID 6 will protect a 24-camera site through a rebuild.

Who it is for

CCTV installers who want to stop guessing on storage capacity, IT support staff who have inherited a customer’s NVR, and anyone designing systems for premises with retention obligations under the UK GDPR or sector-specific regulation (banking, regulated childcare, licensed premises).

Why it matters

The Surveillance Camera Code of Practice expects retention periods to be defined and justified, not arbitrary. A premises that says “we keep 30 days” needs storage sized for that, monitoring that detects a failed drive before footage is lost, and a documented procedure for exporting evidence. Get any of those wrong and the system fails its first real test.

Lessons in this module

Lessons:

Hard Drive Installation in DVR, NVR Part1 (mechanical)
Hard Drive Installation in DVR, NVR Part2 (initialization)
CCTV Storage Types
RAID in CCTV Systems
Software Controllers for RAID in CCTV

 

This module is also available as a part of a comprehensive CCTV Installation Course for £149.