A full disk should not be a surprise. Some recorders may stop at full storage or overwrite older recordings. Check the selected setting and what should happen to important segments before they fall outside the available history.
Look in the model manual for the options available for a full disk. Note the active selection before changing it. Also check if a disk error or unrecognized disk is reported: that is a different situation than a healthy disk whose space has been completely used.
A fragment that is important for an incident must be exported and checked in a timely manner. Do not rely on the assumption that it will always remain on the recorder. Determine who is performing such an export and where the file will end up on the managed location. Also open the file there actually.
How far back the timeline goes can change when more cameras are connected or recording settings are modified. Therefore, look at the actual oldest recording available. Make separate arrangements to determine which storage needs apply and have it assessed whether the capacity and settings match those requirements.
If the model supports locked files, disk groups, or quotas, then explain how those affect the available space. An exception may lead to different behavior than the general setting suggests. Make such choices in the transfer instead of simply enabling the transfer button.
Later, view a recent recording and the earliest available time. Check the storage status for warnings. You do not need to artificially fill in a disk or delete existing images to perform a first check. If in doubt, ask for an explanation of the model settings and the current storage status.
Older recordings may disappear within the set storage cycle. Export important fragments in a timely manner and check the copy.
Not automatically. Extra cameras or other recording settings may affect the available history.
