How do I remove unused kernels in Ubuntu?
The procedure to delete all unused old kernels on Ubuntu Linux version 18.04 and 20.04 LTS is as follows:
- First, boot into a new kernel.
- List all other older kernel using the dpkg command.
- Note down system disk space usage by running the df -H command.
- Delete all unused old kernels, run: sudo apt –purge autoremove.
How do I change kernel in Ubuntu?
How Do I Change the Default Boot Kernel in Ubuntu?
- Assume that the desired default kernel to boot from is the third one. Open the /etc/default/grub file and change the value of GRUB_DEFAULT to “1>2”, as shown in Figure 1.
- Run the following command to rebuild a grub configuration file: # update-grub.
How do I remove old packages from Ubuntu?
7 Ways to Uninstall Ubuntu Packages
- Remove With Ubuntu Software Manager. If you run Ubuntu with the default graphical interface, you may be familiar with the default software manager.
- Use the Synaptic Package Manager.
- Apt-Get Remove Command.
- Apt-Get Purge Command.
- Clean Command.
- AutoRemove Command.
How to roll back the kernel version on Ubuntu?
If you have direct access to the server, you can select “Advanced options for Ubuntu” in the grub menu when you start the system and then select the correct kernel, but after restarting the system, the newest will still start. To start the system from a previous kernel version, open the grub configuration file in a text editor:
Where do I find the kernel version in Ubuntu?
Logs of installing updates if you can see anything in /var/log/dpkg.log and /var/log/apt/. If you have direct access to the server, you can select “Advanced options for Ubuntu” in the grub menu when you start the system and then select the correct kernel, but after restarting the system, the newest will still start.
Can you boot from previous version of kernel?
Sometimes after updating the kernel of the system, some important services start to work incorrectly and in order not to look for a problem on the combat server, and to do it for example later on the virtual one, you can boot the system from the previous version of the kernel.
Is it possible to go back to previous version of Ubuntu?
However the result you end up with is not the same as what you had before the upgrade. During an upgrade certain one-way changes are made to make new packages happy and downgrading them won’t reverse those edits. It’s impossible to guarantee a downgrade will work at all, let alone if it’ll be stable.