How to disable ACPI in CentOS/RHEL 7

ACPI stands for Advanced Configuration and Power Interface. It is the system that controls hardware actions such as the dynamic speed fans, the power button behavior, system sleep states, and helps to identify some system capabilities.

ACPI power-saving features are hierarchical, meaning that any device running “behind” another will be dependent on the power state of the parent device. For example, a device cannot be running in full power “behind” a device that is sleeping or in standby mode.

How to disable ACPI completely in grub2?

For an MBR (BIOS-based) system

1. Make copy of the GRUB2 configuration files before making any changes to them.

# cp /etc/default/grub /etc/default/grub-backup
# cp /boot/grub2/grub.cfg /boot/grub2/grub.cfg-backup

2. Open the /etc/default/grub file and append “noacpi acpi=off” to the GRUB_CMDLINE_LINUX option:

# vi /etc/default/grub
...
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet noacpi acpi=off"

3. Once the file is edited, save it and run the command specified below to generate a new grub.cfg file:

# grub2-mkconfig -o /boot/grub2/grub.cfg

4. Finally, reboot the system to apply the changes:

# systemctl reboot

For a GPT (UEFI-based) system