Guspaz wrote:
Right, and Lassie, which is enabled by default, unless I'm mistaken, is simulating the behaviour of a real computer for reboots...
Only if you have a real computer that always reboots regardless of how you shut down the system. Lassie is an unconditional restart if it sees the guest go down (without a manager shutdown job). Most regular systems need the reboot to be initiated by the same process doing the shut down. Lassie is more akin to a hardware power switch with watchdog wired up to a real computer.
Thus, as pclissold pointed out, you can do a regular shutdown (no reboot) from the guest, and Lassie will still initiate a restart. That caught me by surprise once with my first Linode when I did a shutdown from the guest so I could work with the disks, and didn't expect the Lassie restart, since I erroneously considered it a proper (not unexpected) shutdown. I'm not sure if the manager had the text it now does explaining that unexpected meant no prior shutdown job in the manager itself. (it's certainly plausible it did and I just missed it)
Anyway, essentially a maintenance shutdown has to be done from the manager (if Lassie is enabled). Though if you want the reboot, a guest shutdown (with Lassie) is certainly fine and as clean as through the manager. In that case the shutdown options won't matter - you're going to get a reboot regardless. A guest initiated shutdown is faster (in my experience) than a manager shutdown, but the Lassie restart is then slower than the restart job a manager reboot queues up, so not sure which reboot approach is faster overall.
-- David