dhcp-leasefile=/dev/null logs 'failed to write /dev/null: Invalid argument'
every lease; leasefile-ro is the supported way to run without a lease file.
mirach and almach have each hung at least twice since July with nothing in
the journal or pstore, and stayed down until someone power-cycled the board.
RuntimeWatchdogSec was 0 and kernel.panic was 0, so a hung kernel/PID1 or a
panic could never self-recover.
Arm the systemd hardware watchdog (30s) and reboot 10s after a panic on all
phonebox nodes. Watchdog resets will show up as extra entries in
journalctl --list-boots.
kurogeek