Well, I finally bit the bullet. My laptop, which runs jessie, got dist-upgraded for the first time in a few months. My brightness keys stopped working, and it no longer would suspend to RAM when the lid was closed, and upon chasing things down from XFCE to policykit, eventually it appears that suddenly major parts of the desktop breaks without systemd in jessie. Sigh.
So apt-get install systemd-sysv (and watch sysvinit-core get uninstalled) and reboot.
Only, my system doesn’t come back up. In fact, over several hours of trying to make it boot with systemd, it failed in numerous spectacular and hilarious (or, would be hilarious if my laptop would boot) ways. I had text obliterating the cryptsetup password prompt almost every time. Sometimes there were two processes trying to read a cryptsetup password at once. Sometimes a process was trying to read that while another one was trying to read an emergency shell password. Many times it tried to write to /var and /tmp before they were mounted, meaning they *wouldn’t* mount because there was stuff there.
I noticed it not doing much with ZFS, complaining of a dependency loop between zfs-mount and $local-fs. I fixed that, but it still wouldn’t boot. In fact, it simply hung after writing something about wall passwords.
I’ve dug into systemd, finding a “unit generator for fstab” (whatever the hack that is, it’s not at all made clear by systemd-fstab-generator(8)).
In some cases, there’s info in journalctl, but if I can’t even get to an emergency mode prompt, the practice of hiding all stdout and stderr output is not all that pleasant.
I remember thinking “what’s all the flaming about?” systemd wasn’t my first choice (I always thought “if it ain’t broke, don’t fix it” about sysvinit), but basically ignored the thousands of messages, thinking whatever happens, jessie will still boot.
Now I’m not so sure. Even if the thing boots out of the box, it seems like the boot process with systemd is colossally fragile.
For now, at least zfs rollback can undo upgrades to 800 packages in about 2 seconds. But I can’t stay at some early jessie checkpoint forever.
Have we made a vast mistake that can’t be undone? (If things like even *brightness keys* now require systemd…)