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Kernel boot options

MAAS can specify kernel boot options to machines on both a global basis and a per-machine basis. A full catalog of available options can be found in the Linux kernel parameters list at kernel.org.

Quick questions you may have:

Global kernel boot options

To set kernel boot options globally, as an admin, open the ‘Settings’ page and on the ‘General’ tab scroll down to the ‘Global Kernel Parameters’ section:

global

Type in the desired (space separated) options and click ‘Save’. The contents of the field will be used as-is. Do not use extra characters.

CLI

You can set kernel boot options and apply them to all machines with the CLI command:

maas $PROFILE maas set-config name=kernel_opts value='$KERNEL_OPTIONS'

Per-machine kernel boot options

Per-machine kernel boot options are set using the CLI.

[note] Per-machine boot options take precedence to global ones. [/note]

To specify kernel boot options for an individual machine, first create a tag:

maas $PROFILE tags create name='$TAG_NAME' \
    comment='$COMMENT' kernel_opts='$KERNEL_OPTIONS'

For example:

maas $PROFILE tags create name='nomodeset' \
    comment='nomodeset kernel option' kernel_opts='nomodeset vga'

Next, assign the tag to the machine in question:

maas $PROFILE tag update-nodes $TAG_NAME add=$SYSTEM_ID

If multiple tags attached to a machine have the kernel_opts defined, MAAS uses the first one found, in alphabetical order.

See the CLI tag management section for more information about using the CLI to manage tags.