I know this is not specifically caused by Metabase, but I think it makes sense to post the question here since anyone who would run Metabase on Debian/Ubuntu will run into this problem.
I followed the guide at https://www.metabase.com/docs/latest/operations-guide/running-metabase-on-debian.html
In the environment file /etc/default/metabase
I have added:
JAVA_OPTS=-Xmx2g
Upon stopping and starting the service, the JVM still says it only has access to 1GB of RAM
INFO metabase.util :: Maximum memory available to JVM: 968.0 MB
I tried wrapping it in single quotes and double quotes. No luck.