DieselMig error after changing to mergerfs

I’ve started to use mergerfs to create a virtual fs and I want to use it for my nextcloud and bitwarden. Nextcloud has no issues with it, but vaultwarden can’t seem to work with it. I’ve already added ‘ENABLE_DB_WAL: ‘false’’ to the environment, but I still get this error:

[2021-08-13 14:52:57.101][vaultwarden::util][WARN] Can’t connect to database, retrying: DieselMig.
[CAUSE] QueryError(
DatabaseError(
__Unknown,
“disk I/O error”,
),
)

my config:

bitwarden:
image: vaultwarden/server:latest
volumes:
- $NEXTCLOUD_PATH/bitwarden:/data
environment:
WEBSOCKET_ENABLED: ‘true’ # Required to use websockets
SIGNUPS_ALLOWED: ‘true’ # set to false to disable signups
ENABLE_DB_WAL: ‘false’
deploy:
mode: replicated
replicas: 1
restart_policy:
condition: on-failure
restart: always
networks:
- nextcloud-net

WAL can only be disabled upon creation, or afterwards with some custom sqlite3 commands. Not at runtime or during usage.

You probably need to execute PRAGMA journal_mode=DELETE; on the file. Or, if there is no data in it yet, just delete db.sqlite3 and let Vaultwarden re-create the file without WAL enabled.