Chapter 12. Installing Multiple Kernel Versions

Chapter 12. Installing Multiple Kernel Versions¶

Contents

12.1. Enabling Multiversion Support
12.2. Installing/Removing Multiple Kernel Versions with YaST
12.3. Installing/Removing Multiple Kernel Versions with zypper

openSUSE supports the parallel installation of multiple kernel versions. When installing a second kernel, a boot entry and an initrd are automatically created, so no further manual configuration is needed. When rebooting the machine, the newly added kernel is available as an additional boot option.

Using this functionality, you can safely test kernel updates while being able to always fall back to the proven former kernel. To do so, do not use the update tools (such as the YaST Online Update or the updater applet), but instead follow the process described in this chapter.

	Support Entitlement
Please be aware that you loose your entire support entitlement for the machine when installing a self-compiled or a third-party kernel. Only kernels shipped with openSUSE and kernels delivered via the official update channels for openSUSE are supported.

Check Your Bootloader Configuration Kernel

	Check Your Bootloader Configuration Kernel
It is recommended to check your bootloader config after having installed another kernel in order to set the default boot entry of your choice. See Section “Configuring the Boot Loader with YaST” (Chapter 18, The Boot Loader GRUB, ↑Reference) for more information. To change the default append line for new kernel installations, adjust `/etc/sysconfig/bootloader` prior to installing a new kernel. For more information refer to Section “The File `/etc/sysconfig/bootloader`” (Chapter 18, The Boot Loader GRUB, ↑Reference).

It is recommended to check your bootloader config after having installed another kernel in order to set the default boot entry of your choice. See Section “Configuring the Boot Loader with YaST” (Chapter 18, The Boot Loader GRUB, ↑Reference) for more information. To change the default append line for new kernel installations, adjust /etc/sysconfig/bootloader prior to installing a new kernel. For more information refer to Section “The File /etc/sysconfig/bootloader” (Chapter 18, The Boot Loader GRUB, ↑Reference).

12.1. Enabling Multiversion Support¶

Installing multiple versions of a software package (multiversion support) is not enabled by default. To enable this feature, proceed as follows:

Open /etc/zypp/zypp.conf with the editor of your choice as root, for example
```
sudo vi /etc/zypp/zypp.conf
```
Search for the string multiversion. To enable multiversion for all kernel packages capable of this feature, uncomment the following line
```
# multiversion = provides:multiversion(kernel)
```
by removing the # character.
To restrict multiversion support to certain kernel flavors, specify the package names as a comma-separated list, for example
```
multiversion = kernel-default,kernel-default-base,kernel-source
```
Save your changes.

12.2. Installing/Removing Multiple Kernel Versions with YaST¶

Start YaST and open the software manager via Software+Software Mannagment.
List all packages capable of providing multiple versions by choosing View+Package Groups+Multiversion Packages.
Figure 12.1. The YaST Software Manager - Multiversion View
Select a package and open its Version tab in the bottom pane on the left.
To install a package, click its checkbox. A green checkmark indicates it is selected for installation.
To remove an already installed package (marked with a white checkmark), click its checkbox until a red X indicates it is selected for removal.
Click Accept to start the installation.

12.3. Installing/Removing Multiple Kernel Versions with zypper¶

Use the command zypper se -s 'kernel*' to display a list of all kernel packages available:


S | Name           | Type       | Version         | Arch   | Repository        
--+----------------+------------+-----------------+--------+-------------------
v | kernel-default | package    | 2.6.32.10-0.4.1 | x86_64 | Alternative Kernel
i | kernel-default | package    | 2.6.32.9-0.5.1  | x86_64 | (System Packages) 
  | kernel-default | srcpackage | 2.6.32.10-0.4.1 | noarch | Alternative Kernel
i | kernel-default | package    | 2.6.32.9-0.5.1  | x86_64 | (System Packages)
...

Specify the exact version when installing:
```
zypper in kernel-default-2.6.32.10-0.4.1
```
When uninstalling a kernel, use the commands zypper se -si 'kernel*' to list all kernels installed and zypper rm PACKAGENAME-VERSION to remove the package.