= Booting
JetStream
:revnumber: unspecified
:revdate: 2021-10-11
:category: Kernel
:tags: How-to, Kernel 
:page-aliases: kernel/booting.adoc 



== Setting an installed kernel to boot by default

To set a specific installed kernel to boot by default, first check the kernels installed on the system.

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sudo ls /boot | grep vmlinuz
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Identify the kernel to be set to boot by default.

Use the following command to set the default kernel to boot:

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sudo grubby --set-default /boot/vmlinuz-<version>.<release>.<arch>
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Here is a sample output (on an `x84_64` architecture system):

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sudo ls /boot | grep vmlinuz

vmlinuz-0-rescue-c722f5f7d614446b99c39b846c2bb76c
vmlinuz-5.12.18-200.fc33.x86_64
vmlinuz-5.8.15-301.fc33.x86_64
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If `vmlinuz-<version>.<release>.<arch>` is chosen to be set as the default, we issue the following command:

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sudo grubby --set-default /boot/vmlinuz-<version>.<release>.<arch>
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For the above scenario, the command will look like so

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sudo grubby --set-default /boot/vmlinuz-5.12.18-200.fc33.x86_64
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[[sect-references]]
=== References:

* https://docs.fedoraproject.org/en-US/fedora/rawhide/system-administrators-guide/kernel-module-driver-configuration/Working_with_the_GRUB_2_Boot_Loader/[Fedora Rawhide Docs :: Working with the GRUB 2 Boot Loader]