Shutdown / reboot
| Solaris | Red Hat | Ubuntu / Debian | HP-UX | AIX |
|---|
| Power down | shutdown -i5 -g0 -y | shutdown -h | shutdown -h | shutdown -h now | shutdown -F |
| Reboot | shutdown -i6 -g0 -y | shutdown -r | shutdown -r | shutdown -r now | shutdown -Fr |
| OK prompt | shutdown -i0 -g0 -y | — | — | — | — |
| Fast | reboot -- -r (reconfigure) | shutdown -f (no fsck) | shutdown -P (power off) | shutdown -F (force fsck) | — |
| Force fsck | touch /reconfigure | touch /forcefsck | edit /etc/default/rcS → FSCKFIX=yes | — | — |
Change runlevel
| Tool | Solaris | Red Hat | Ubuntu / Debian | HP-UX | AIX |
|---|
halt | ✅ | ✅ | ✅ | ✅ | ✅ |
init | ✅ | ✅ | ✅ | ✅ | ✅ |
poweroff | ✅ | ✅ | ✅ | ✅ | ✅ |
reboot | ✅ | ✅ | ✅ | ✅ | ✅ |
shutdown | ✅ | ✅ | ✅ | ✅ | ✅ |
telinit | ✅ | ✅ | ✅ | — | ✅ |
uadmin | ✅ | — | — | — | — |
Runlevels
| Level | Solaris | Red Hat | Ubuntu / Debian | HP-UX | AIX |
|---|
| 0 | shutdown | halt | halt | halt | reserved |
| 1 | single user | single user | single user | single user | reserved |
| 2 | n/a | multiuser (no networking) | multiuser (default) | multiuser (networking) | multiuser + NFS |
| 3 | multi-user | multiuser (networking) | same as 2 | multiuser + NFS + CDE GUI (default) | user defined |
| 4 | n/a | unused | same as 2 | multiuser + NFS + VUE GUI | user defined |
| 5 | power off | GUI | same as 2 | n/a | user defined |
| 6 | reboot | reboot | reboot | n/a | user defined |
| 7-9 | — | — | — | — | user defined |
Change the default runlevel
- Solaris / Red Hat / HP-UX / AIX : edit the
initdefault line in vi /etc/inittab. - Ubuntu / Debian : edit
vi /etc/event.d/rc-default.
On systemd systems (RHEL 7+, Ubuntu 15+), the SysV runlevels are replaced by targets — e.g. systemctl isolate multi-user.target (runlevel 3), systemctl isolate graphical.target (runlevel 5), systemctl set-default multi-user.target. See the Systemd page.