By default, the DVR content will reside for 24 hours from the time of recording.
You can set the retention period for the DVR. So the recordings will be available on the server for that specified days.
What is the maximum limit that I can set as the retention period?
You can set the retention period up to 90 days. So the recordings will be available for 90 days maximum. Also, you can export the recordings to cloud storage for permanent storage.