[ceph-users] mons with "low on available space" message

Hi! its about my Lab setup. As I didn't have a thought about the space requirements for the root file system I want to know if there is a rule by thumb how much space a cpeh mon might need? rightnow I only have the "whoami" container running in rook-ceph so it does consume nearly no space in the OSD. But how far can I go with only 1.7 GB left on my Raspberry Pi's sdcard? Greetings filip