mweishaar wrote:

when were runlevels 2-5 made the same?

AFAIK runlevels 2-5 have always been the same in Debian but I've only been using it since wheezy so I might be wrong.

Reference: https://wiki.debian.org/RunLevel

But note that in Debian under systemd runlevels 2,3 & 4 are simulated as multi-user.target (which is a console-only boot) whereas runlevel 5 is simulated as graphical.target (which is a graphical boot):

$ ls -l /lib/systemd/system/runlevel?.target 
lrwxrwxrwx 1 root root 15 Jan 29 14:16 /lib/systemd/system/runlevel0.target -> poweroff.target
lrwxrwxrwx 1 root root 13 Jan 29 14:16 /lib/systemd/system/runlevel1.target -> rescue.target
lrwxrwxrwx 1 root root 17 Jan 29 14:16 /lib/systemd/system/runlevel2.target -> multi-user.target
lrwxrwxrwx 1 root root 17 Jan 29 14:16 /lib/systemd/system/runlevel3.target -> multi-user.target
lrwxrwxrwx 1 root root 17 Jan 29 14:16 /lib/systemd/system/runlevel4.target -> multi-user.target
lrwxrwxrwx 1 root root 16 Jan 29 14:16 /lib/systemd/system/runlevel5.target -> graphical.target
lrwxrwxrwx 1 root root 13 Jan 29 14:16 /lib/systemd/system/runlevel6.target -> reboot.target
$

Thanks.  I started with Redhat in '98, then Mandrake in '02, and have been on Debian-based distros since '05 with Kubuntu/Xubuntu/Mint.  I've only been on Devuan since 2018.

I don't speak systemd - at least not yet. 

when were runlevels 2-5 made the same?

AFAIK runlevels 2-5 have always been the same in Debian but I've only been using it since wheezy so I might be wrong.

Reference: https://wiki.debian.org/RunLevel

But note that in Debian under systemd runlevels 2,3 & 4 are simulated as multi-user.target (which is a console-only boot) whereas runlevel 5 is simulated as graphical.target (which is a graphical boot):

$ ls -l /lib/systemd/system/runlevel?.target 
lrwxrwxrwx 1 root root 15 Jan 29 14:16 /lib/systemd/system/runlevel0.target -> poweroff.target
lrwxrwxrwx 1 root root 13 Jan 29 14:16 /lib/systemd/system/runlevel1.target -> rescue.target
lrwxrwxrwx 1 root root 17 Jan 29 14:16 /lib/systemd/system/runlevel2.target -> multi-user.target
lrwxrwxrwx 1 root root 17 Jan 29 14:16 /lib/systemd/system/runlevel3.target -> multi-user.target
lrwxrwxrwx 1 root root 17 Jan 29 14:16 /lib/systemd/system/runlevel4.target -> multi-user.target
lrwxrwxrwx 1 root root 16 Jan 29 14:16 /lib/systemd/system/runlevel5.target -> graphical.target
lrwxrwxrwx 1 root root 13 Jan 29 14:16 /lib/systemd/system/runlevel6.target -> reboot.target
$

Always test and verify!  After modifying a grub entry at boot time and appending runlevel 3, it still launched into X.  I checked my runlevel using who -r and confirmed I was in 3.  Ok, so I had to do more research, and dig into grub and runlevels.  This is where I discovered that all my old dusty knowledge didn't apply anymore.  Default runlevel is 2, not 5.  And it wouldn't matter if I changed it to 5, because all runlevels 2-5 in /etc/rc#.d were identical.  I eventually modified runlevel 3 to boot without X by disabling slim  sudo update-rc.d slim disable 3, then created a custom boot entry for runlevel 3 in /etc/grub.d/40_custom and added it to grub with sudo update-grub.  Works as expected, no X.

This post is mainly for posterity.  Even though I've been using linux for 20+ years I learned something, including that you don't need an xorg.conf file anymore. 

Out of curiosity, when were runlevels 2-5 made the same?  Was it in Debian pre-systemd or is it a Devuan thing?