I have a (x)Ubuntu machine I primarily use as a server, that I've been upgrading from LTS release to LTS release ever since Hardy Heron 8.04.
It's gone all to **** now it seems since upgrading to Xenial which coincides with the transition to systemd.
The first problem is the system doesn't come up properly after a reboot about half of the time. I've seen it refuse to start X, where it seems hardly any services started properly. When it does start into X, about half of the time the network didn't come up, I'm assuming because network manager didn't start. When it does come up mostly normal, it seems that some services need to be restarted still because they started before the network was up, which shouldn't happen.
None of this was happening before Xenial, and I blame systemd. System is stable once it's up.
Thoughts? It's a pretty kludged system since some of my distro updates didn't go smoothly, and it's been upgraded several times, starting as a plain Ubuntu system, then moving to XFCE once the Gnome2 wasn't an option, I've also upgraded different things at time by compiling packages from source and making a mess of things, but I feel this is more Ubuntu's fault than mine.
I recall reading that systemd was supposed to start more things in parallel or something to speed boot times (system doesn't seem to boot any faster that before), so I'm highly suspect of systemd, but maybe I need to do some purging of upstart to do? Upstart seems like it is still installed among lots of other cruft no doubt.