What you'll notice
The event you need has already been recorded over — retention is only a few days.
Why it happens
A drive too small for the camera count and resolution, recording at maximum bitrate unnecessarily, or continuous recording where smart/motion recording would do.
How we fix it
We rebalance bitrate and recording modes, and size additional or replacement storage to hit the retention target you choose — stated in days, in writing.
Still not working?
If the checks above haven't restored your surveillance hard drive, this usually needs a technician. Our CCTV Hard Drive Replacement service covers exactly this fault.