# Grub

#### Setting the default runlevel in Ubuntu 16.04

Mapping between runlevels and systemd targets  
  
Runlevel / Target

0: poweroff.target  
1: rescue.target  
2, 3, 4: multi-user.target  
5: graphical.target  
6: reboot.target

To change runlevel:

sudo systemctl isolate multi-user.target

  
To set the default runlevel:

sudo systemctl enable multi-user.target  
sudo systemctl set-default multi-user.target

#### Adding Operating Systems to Linux grub bootloader

Open a new terminal  
Execute the following commands:

```
sudo os-prober		#this will search for the OSs
sudo update-grub	#this will update your grub bootloader
```