[systemd] /tmp in container only using 20% of host's available /tmp


I just noticed a “new” behaviour when using a systemd container: the available space on /tmp (tmpfs) inside the container is only 20% of what’s available on the host, which by default is 50% of RAM.

Does anyone know how to increase /tmp space in the container?
I didn’t find any specific option, and it also seems to be a new behaviour.

(No, remounting /tmp inside the container with size=xx does not work)

I must have been too tired…
Anyway, found a solution:
Create a nspawn config file in /etc/systemd/nspawn and add
TemporaryFileSystem=/tmp:size=xx to the [Files] section.

Marking as solved.