4 Easy Ways To Get Out Of A Ubuntu Crash

Ubuntu, like any other operating system, can sometimes crash or freeze, leaving users in a frustrating situation. However, there are several effective methods to recover from such crashes and get your system back up and running.

Restarting the Wayland Compositor

One of the most common causes of a crash on Ubuntu is an unresponsive Wayland daemon, which manages the graphical environment. To address this, you can restart the Wayland server.

1. Switch to a TTY Session: Press Ctrl + Alt + F3 to switch to a TTY session. If this doesn't work, try different function keys or press Alt + SysRq + R first.

2. Restart the Display Manager: Once in the console, sign in and restart the display manager using the command:

   sudo systemctl restart gdm
   

   For KDE users, replace gdm with sddm.

3. Terminate the Session: If restarting the display manager doesn't work, you can terminate your entire session with:

   sudo pkill -KILL -u $USER
   

4. Reboot the System: If all else fails, you can reboot the system with:

sudo reboot

SSH into Your System

If accessing the console directly is not possible, you can try SSHing into your system from another machine.

1. Ensure SSH is Enabled: Make sure SSH is enabled on your Ubuntu system. You can enable it by running:

   sudo apt install openssh-server
   

2. Connect via SSH: From another machine, connect to your Ubuntu system using SSH:

   ssh username@ip-address
   

3. Restart Services or Reboot: Once connected, you can restart services or reboot the system as needed.

Using the Magic SysRq Key

The Magic SysRq key combination is a powerful tool for recovering from a frozen system.

1. Enable Magic SysRq: Ensure that the Magic SysRq key is enabled by editing the configuration file:

   sudo nano /etc/sysctl.d/10-magic-sysrq.conf
   

   Uncomment the line kernel.sysrq = 1 to enable it.

2. Use the Magic SysRq Keys: Press Alt + SysRq and then one of the following keys:
   • B: Reboot the system.
   • E: Send a terminate signal to all processes except for init.
   • S: Synchronize all mounted file systems.
   • I: Send a kill signal to all processes except for init.
   • U: Remount file systems as read-only.
   • R: Activate XLATE mode (requires configuration changes).

Chroot from a Live CD

If your system is completely unbootable, you can use a live CD to chroot into your system and perform repairs.

1. Boot from a Live USB: Insert a Ubuntu live USB, boot your computer, and select "Try Ubuntu."
2. Mount Partitions: Open a terminal and mount your system's partitions:

   sudo mkdir /media/recovery
   sudo mkdir /media/recovery/boot
   sudo mount /dev/sda2 /media/recovery
   sudo mount /dev/sda1 /media/recovery/boot
   

   Replace /dev/sda2 and /dev/sda1 with your actual partition labels.

3. Mount System Directories: Mount necessary system directories:

   sudo mount -t proc /proc /media/recovery/proc
   sudo mount --rbind /sys /media/recovery/sys
   sudo mount --make-rslave /media/recovery/sys
   sudo mount --rbind /dev /media/recovery/dev
   sudo mount --make-rslave /media/recovery/dev
   sudo mount --bind /run /media/recovery/run
   sudo mount --make-slave /media/recovery/run
   

4. Chroot into the System: Change the root directory to your crashed system:

   sudo chroot /media/recovery
   source /etc/profile
   

5. Perform Repairs: Now you can debug and repair your system. Common tasks include restoring the GRUB bootloader or running Apt to repair package issues.

By following these steps, you can effectively recover from a Ubuntu crash and get your system back to a stable state.