After upgrading my Jessie machines to Stretch, they no longer cleanly reboot, even if using the Jessie kernel. I tried reboot=BIOS, ACPI, PCI, even force=ACPI, but none work. The reboot hangs on:
[ OK ] Removed slice system-postfix.slice
but it's still alive - I can keep pressing Ctrl+Alt+Delete and get:
[447.012345] systemd-shutdow: 35 output lines suppresed due to ratelimiting [447.012346] systemd-shutdown: Sending SIGTERM to remaining processes... [447.012347] systemd-journal: Received SIGTERM from PID 1 (systemd-shutdow).
Then it freezes for about 90 seconds (suppose
system.conf) and then finally reboots. This happens on both systems I've upgraded to Jessie.
I also tried
swapoff -a, to no effect.