How a Tesla records Dashcam & Sentry footage

Here's how Dashcam/Sentry recording works in a nutshell, assuming a USB drive is present:

• the car is always recording as long as it is "on", except while you're using "theater mode" to e.g. watch Netflix or YouTube.
• the car records a series of sets of 1-minute recordings, one for each camera angle.
• the recording files are first written to some internal storage, not the USB drive
• when a set of 1-minute recordings is complete, those recording are moved from internal storage to the RecentClips folder on the USB drive and it starts a new set of recordings in internal storage
• the car keeps an hour's worth of RecentClips recordings¹ and deletes older recordings (on older Tesla firmware it appeared to delete recordings older than an hour, even if that meant deleting everything). If you're using a normal USB drive these deleted recordings will become unrecoverable after some time because the disk space will be overwritten by new recordings².
• if Sentry mode is on and a Sentry event is detected, it continues recording for a little while, then moves the last 1-12 minutes of recordings from RecentClips into a timestamped folder under SentryClips.
• when you do a manual save, it saves the last 10 minutes of recordings from RecentClips to a timestamped folder under SavedClips. This often results in loss of the last recorded bit of video, so it's best to wait a few minutes before doing a manual save.

<sup>1. This may be country-dependent. It has been reported to only keep 10 minutes of RecentClips in Germany.
2. Teslausb takes regular snapshots of the emulated USB drive to preserve recordings before the car deletes them, and only deletes them when the disk space is actually needed.</sup>