Distinguish a full disk from an unreadable disk

Many recorders fill the surveillance volume and then overwrite the oldest footage. In that normal state, free space may remain near zero while total capacity is correct and recording continues.

Total capacity of zero, an offline status or stopped recording indicates a different problem.

Verify overwrite and retention settings

Check recycle, overwrite or automatic deletion settings. A recorder configured to stop when full will require manual cleanup or a policy change. Preserve clips required for legal, insurance or security purposes before deletion.

Check the oldest available recording

When overwrite is working, the oldest recording date should move forward over time while new footage is added. If neither old nor new footage changes, the storage database or write path may be stuck.

Confirm the drive's total capacity

A high-capacity disk showing only part of its size may exceed a recorder limit or be affected by an old partition layout. Check the exact recorder model and firmware before reinitializing.

Do not format before exporting required footage

Initialization and formatting normally erase the recorder's index and recordings. If clips matter, export them before attempting volume repair.

Inspect disk status, power and health

An NVR may report 0GB when it loses the disk, cannot mount the volume or encounters repeated read/write errors. Review SMART or SHM warnings, event logs, temperature and power stability.

Calculate whether the installed capacity is sufficient

Retention depends on bitrate rather than resolution labels alone. More cameras, higher frame rates, audio and continuous recording increase daily storage. Motion recording and H.265 can reduce use when configured appropriately.

Replace or expand without mixing the diagnosis

Expansion solves a genuine capacity shortage. It does not solve an abnormal disk, unsupported capacity or failing power supply. Diagnose the current storage state first.