To diagnose systemd
related boot issues, you can enable early shell access during boot.
Perform the following steps to enable early shell access:
-
Restart the Photon OS machine or the virtual machine running Photon OS.
When the Photon OS splash screen appears, as it restarts, type the letter
e
quickly. -
Append
systemd.debug-shell=1
to the kernel command line.Optionally, to change logging level to debug, you can append
systemd.log_level=debug
. -
Press
F10
to proceed with the boot. -
Press
Alt+Ctrl+F9
to switch totty9
to access the debug shell.