Tutorials · Video Surveillance
How to Configure NVR Storage, RAID and Retention
Install surveillance drives, choose RAID, set recording quotas and confirm you keep footage for the required number of days.
Before you start
- An NVR with drive bays
- Surveillance-grade hard drives
- Your retention requirement (for example 30 days)
Step by step
Calculate storage
Cameras × bitrate × hours × days. Example: 32 cameras × 4 Mbps × 24 h × 30 days ≈ 41 TB before RAID overhead.
Use surveillance drives
Choose drives rated for 24/7 write workloads.
Choose RAID if supported
RAID 5 survives one drive failure; RAID 6 survives two. On large arrays, prefer RAID 6.
Initialise the drives
Format drives in the NVR and confirm the full capacity is available.
Set recording mode per camera
Continuous for critical areas, event or AI-triggered for low-activity areas to save space.
Use H.265 and sensible settings
H.265 halves storage compared with H.264. Reduce frame rate where motion is slow.
Configure overwrite and quotas
Enable overwrite of the oldest footage, or set per-camera quotas so important cameras keep longer history.
Check retention
After a week, check the oldest available recording and extrapolate.
Monitor drive health
Enable alerts for drive errors and RAID degradation.
Pro tips
- Keep a spare drive on site.
- Export important incidents immediately; overwrite is automatic.
FAQ
Frequently asked questions
How long should CCTV be kept?
Follow local law and your policy; 30 days is common for businesses, longer for some regulated sites.
Keep learning
Related guides
CCTV storage calculation
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Read more →Stuck on a step?
Ask Navijin technical support or an authorised partner for help with your configuration.