df -Ph

|Filesystem| Size|Used|Avail|Use%|Mounted on |---|---|---|---|---||---| tmpfs|497M|497M|0|100%|/run

du -h /run

447M    /run/systemd

du -h /run/systemd

447M    /run/systemd/sessions

TrevorH: "It would appear that updates to systemd now require a reboot to avoid this sort of problem and others related to it. The problem appears to be a known one upstream and newer systemd versions have been fixed - it's to do > with losing its dbus connection."

reboot

|Filesystem| Size|Used|Avail|Use%|Mounted on |---|---|---|---|---|---| tmpfs|497M|6.7M|490M|2%|/run