Oracle Linux and Solaris runlevels

A runlevel is a preset operating state on a Unix-like operating system.

A system can be booted into (i.e., started up into) any of several runlevels, each of which is represented by a single digit integer. Each runlevel designates a different system configuration and allows access to a different combination of processes (i.e., instances of executing programs).

The are differences in the runlevels according to the operating system. RHEL 6 and Solaris have runlevels 0 through 6 although the meanings are different. In RHEL 7 a runlevel is known as a target.

Runlevel/Target Meaning
OEL 6 / Solaris OEL 7 OEL Solaris
0 poweroff.target Power-off state OS stopped, OBP still running
s (or S) Single user
1 rescue.target Single user System management state
2 not used Multi-user (no NFS)
3 multi-user.target Multi-user Multi-user (default)
4 not used multi-user (user defined services)
5 graphical.target X window (default) Power-off state
6 reboot.target OS restart OS restart

The Solaris OS runlevels to keep in mind are 0 (OS stopped), s (single-user), 3 (multi-user), 5 (power-off) and 6 (restart).

OS boot/stop commands

Basic Operation Oracle Enterprise Linux Oracle Solaris
OEL 6 OEL 7
Start OS Start from the GRUB menu Start from the GRUB2 menu Execute the start command from the OBP (OpenBoot PROM) environment.
{0} ok boot
Start in single-user mode Add a runlevel.
kernel /vmlinuz-...
root=... 1
Add a runlevel.
systemd.unit=
rescue.target
Start in single user mode from the OBP (OpenBoot PROM) environment.
{0} ok boot -s
Stop OS Specify the stop option (-h) in the shutdown command.
# shutdown -h now
Specify the stop option (poweroff) in the systemctl command.
# systemctl poweroff
Execute the shutdown command. Specify the stop option (-i5).
# shutdown -y -g0 -i5
Restart OS Specify the restart option (-r) in the shutdown command.
# shutdown -r now
Specify the restart option (reboot) in the systemctl command.
# systemctl restart
Execute the shutdown command. Specify the restart option (-i6).
# shutdown -y -g0 -i6
Other examples Stop at 10 o'clock.
# shutdown -h 10:00
Stop after 5 minutes.
# shutdown -h +5
Suspend the OS.
# systemctl suspend
Hibernate the OS
# systemctl hibernate
Start via network
{0} ok boot net:dhcp
Restart after 30 seconds
# shutdown -y -g30 -i6