Ability to specify multiple storage locations

I would like to be able to use multiple ways to store records.
It will be useful when there are several disks on the device.

It would also be nice to be able to change the storage location for each camera.

The issue does not name files, tests, or configuration entry points. Start by locating how storage paths and per-camera settings are currently represented, then determine the configuration and migration implications of supporting multiple disks; done should include documented behavior for multiple locations and camera-specific storage.

Written by the indexing model from the issue text.