[conspire] Debian - and NOT systemd! :-)

[Michael Paoli]

Debian - and NOT systemd! :-)

Far too often I hear/see folks saying stuff like:
"I hate systemd, Debian uses systemd, I hate Debian, I won't use
Debian."
And even highly untrue stuff such as:
"Debian at this moment you cannot replace init system" ...
"it is the-only init system." ... "Debian that inits are executed as an
addition to systemd(you simply cannot get rid of systemd"

It gets quite annoying, really it does.
Yes, sure, Debian's default init system has been systemd since the
Debian GNU/Linux 8 "Jessie" released 2015-04-25,
however Debian continues to make available and support other
init systems.  E.g. in the current stable,
Debian GNU/Linux 10 (buster), released 2019-07-06,
Debian offers and supports 3:
systemd
sysvinit
runit
Folks also complain about how "difficult" it is to change.
Well, I call bull on that!

E.g., below I show a Debian host,
at the moment running systemd.
Watch how easily and quickly I change from systemd, to runit, then to
sysvinit, and then back to systemd again:

TZ=GMT0 script -c 'sudo virsh start small.9to10 --console'  
--timing="$HOME"/tmp/bullscript.time ~/tmp/bullscript
Script started on 2020-12-10 23:27:48+00:00 [TERM="screen"  
TTY="/dev/pts/20" COLUMNS="80" LINES="24"]

debian login: root
Password:
# echo $(uname -s -r -v -m -o; cat /etc/debian_version); ls -l  
/proc/1/exe; dpkg -S /sbin/init
Linux 4.19.0-13-amd64 #1 SMP Debian 4.19.160-2 (2020-11-28) x86_64  
GNU/Linux 10.7
lrwxrwxrwx 1 root root 0 Dec 10 23:27 /proc/1/exe -> /lib/systemd/systemd
systemd-sysv: /sbin/init
# apt-get -y --allow-change-held-packages install runit-init  
sysvinit-core- systemd-sysv-
# cd / && sync && sync && reboot -f -f

debian login: root
Password:
# echo $(uname -s -r -v -m -o; cat /etc/debian_version); ls -l  
/proc/1/exe; dpkg -S /sbin/init
Linux 4.19.0-13-amd64 #1 SMP Debian 4.19.160-2 (2020-11-28) x86_64  
GNU/Linux 10.7
lrwxrwxrwx 1 root root 0 Dec 10 23:31 /proc/1/exe -> /sbin/runit
runit-init: /sbin/init
# apt-get -y --allow-change-held-packages install sysvinit-core  
systemd-sysv- runit-init-
# cd / && sync && sync && reboot -f -f

debian login: root
Password:
# echo $(uname -s -r -v -m -o; cat /etc/debian_version); ls -l  
/proc/1/exe; dpkg -S /sbin/init
Linux 4.19.0-13-amd64 #1 SMP Debian 4.19.160-2 (2020-11-28) x86_64  
GNU/Linux 10.7
lrwxrwxrwx 1 root root 0 Dec 10 23:36 /proc/1/exe -> /sbin/init
sysvinit-core: /sbin/init
# apt-get -y --allow-change-held-packages install systemd-sysv  
runit-init- sysvinit-core-
# cd / && sync && sync && reboot -f -f

debian login: root
Password:
# echo $(uname -s -r -v -m -o; cat /etc/debian_version); ls -l  
/proc/1/exe; dpkg -S /sbin/init
Linux 4.19.0-13-amd64 #1 SMP Debian 4.19.160-2 (2020-11-28) x86_64  
GNU/Linux 10.7
lrwxrwxrwx 1 root root 0 Dec 10 23:38 /proc/1/exe -> /lib/systemd/systemd
systemd-sysv: /sbin/init
# cd / && shutdown -h now

Script done on 2020-12-10 23:39:02+00:00 [COMMAND_EXIT_CODE="0"]

Want to watch it in replay in real time (or faster or slower)?
scriptreplay(1)
tar(1)
bzip2(1)
while it lasts:
http://www.mpaoli.net/~michael/tmp/bullscript.tar.bz2
$ echo 'exec >>/dev/null 2>&1; cd /home/m/michael/public_html/tmp &&  
find bullscript.tar.bz2 -type d -prune -o -type f -mtime +90 -exec rm  
-f \{\} \;; :' | (cd / && TZ=GMT0 at now + 95 days)
warning: commands will be executed using /bin/sh
job 62 at Mon Mar 15 23:59:00 2021