CHANGING RUN LEVELS

  1. Open a terminal session
  2. sudo -i  and enter the root password
  3. who -r
    1. will display your current run level
  4. cat /etc/inittab
    1. will list the available run level
  5. Deb/Ubu
    1. telinit <runlevel>
    2. example: telinit 1
      1. will change you to single user for administrative tasks
  6. RHEL/CentOS
    1. systemctl list-units –type=target
    2. example: systemctl isolate runlevel1.target
      1. will change you to single user for administrative tasks
Run Level
Mode
Action
0 Halt Halts the system. Run Level 0 is a not to be used as the default run level, otherwise the system will never come up. Because the system would shutdown the second the kernel launches init process.
1 Single-User Mode/Maintenance Mode Does not configure network interfaces, start daemons, or allow non-root logins
2 Multi-User Mode Debian’s default runlevel. On RHEL, runlevel2 starts without NFS file sharing and without X Window System. (No GUI)
3 Multi-User Mode with Networking RHEL’s default runlevel. Multi-user mode with networking but with no GUI
4 Undefined Not used/User-definable
5 X11 Multi-User mode with X11 started and GUI is running
6 Reboot Reboots the system. Should not be used a the default run level because it will cause infinite reboots
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s