As I migrated my NAS to OpenMediaVault, I already had a big number of pictures that were already organized in a specific folder. Immich has its own folder structure which did not match, so I had to come up with something different
This is the docker-compose.yml I used, where a custom additional folder was added:
#
# WARNING: To install Immich, follow our guide: https://docs.immich.app/install/docker-compose
#
# Make sure to use the docker-compose.yml of the current release:
#