Meu servidor radicale estava travando com as seguintes mensagens de log dejournalctl
Jan 02 04:28:13 RPi64 systemd[1]: Started A simple CalDAV (calendar) and CardDAV (contact) server.
Jan 02 04:28:23 RPi64 systemd[14181]: radicale.service: Failed to set up mount namespacing: /run/systemd/unit-root/: Host is down
Jan 02 04:28:23 RPi64 systemd[14181]: radicale.service: Failed at step NAMESPACE spawning /usr/bin/env: Host is down
Jan 02 04:28:23 RPi64 systemd[1]: radicale.service: Main process exited, code=exited, status=226/NAMESPACE
Jan 02 04:28:23 RPi64 systemd[1]: radicale.service: Failed with result 'exit-code'.
Jan 02 04:29:24 RPi64 systemd[1]: radicale.service: Scheduled restart job, restart counter is at 8.
Jan 02 04:29:24 RPi64 systemd[1]: Stopped A simple CalDAV (calendar) and CardDAV (contact) server.