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linux mitigation disable (debian)

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Commands

linux mitigation disable (debian)
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Adds mitigations=off to the kernel command line, which disables all optional CPU mitigations (Spectre, Meltdown, and the other grouped fixes). Do this only on machines that never run code you don’t control — on a daily driver or shared system, leave them on.

  1. Edit /etc/default/grub as root:

    sudo nano /etc/default/grub

  2. Append mitigations=off to the existing GRUB_CMDLINE_LINUX_DEFAULT value — don’t replace the line, or you lose the distro’s other defaults such as quiet splash:

    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash mitigations=off"

    If your setup puts the options in GRUB_CMDLINE_LINUX instead, edit that one.

  3. Regenerate the GRUB config, then reboot — the change does nothing until the next boot:

    sudo update-grub
sudo reboot

After rebooting, confirm the parameter is live:

grep -o mitigations=off /proc/cmdline

If it is missing, the edit landed on the wrong variable, or something other than GRUB boots this system (update-grub is a Debian wrapper; Arch and friends use grub-mkconfig -o /boot/grub/grub.cfg instead).