System Options 9999 System action on Ctrl-Alt-Delete keystroke ignore reboot poweroff ignore Ignore key sequence reboot Reboot system poweroff Poweroff system (ignore|reboot|poweroff) Must be ignore, reboot, or poweroff Kernel boot parameters CPU settings Disable the NMI watchdog for detecting hard CPU lockups Isolate specified CPUs from the scheduler u32:0-511 CPU core <start-end> CPU core range (examples: "1", "4-7", "1,2-5,7") Enable full tickless mode for specified CPUs u32:0-511 CPU core <start-end> CPU core range (examples: "1", "4-7", "1,2-5,7") Offload Read-Copy-Update (RCU) callback processing to specified CPUs u32:0-511 CPU core <start-end> CPU core range (examples: "1", "4-7", "1,2-5,7") Memory settings Disable automatic NUMA memory balancing Set default hugepage size (e.g., 2M, 1G) 2M 1G 2M 2 megabytes 1G 1 gigabyte (2M|1G) Set hugepage size for allocation (e.g., 2M, 1G) 2M 1G 2M 2 megabytes 1G 1 gigabyte (2M|1G) Allocate number of hugepages for system use u32 Number of hugepages Disable High Precision Event Timer (HPET) Disable Machine Check Exceptions (MCE) reporting and handling Disable all optional CPU mitigations Disable CPU power saving mechanisms also known as C states Enables and configures pstate driver for AMD Ryzen and Epyc CPUs active passive guided active The firmware controls performance states and the system governor has no effect passive Allow the system governor to manage performance states guided The firmware controls performance states guided by the system governor Disable soft lockup detector for kernel threads Disable most log messages Dynamic debugging for kernel module Dynamic debugging for Wireguard module System keyboard layout, type ISO2 us uk fr de es fi it jp106 no dk se-latin1 dvorak us United States uk United Kingdom fr France de Germany es Spain fi Finland it Italy jp106 Japan no Norway dk Denmark se-latin1 Sweden dvorak Dvorak (us|uk|fr|de|es|fi|it|jp106|no|dk|se-latin1|dvorak) Invalid keyboard layout us Tune system performance network-throughput network-latency power-save virtual-host virtual-guest network-throughput Tune for maximum network throughput network-latency Tune for low network latency power-save Tune for low power consumption virtual-guest Tune for running inside a virtual machine virtual-host Tune for running guest virtual machines (network-throughput|network-latency|power-save|virtual-guest|virtual-host) Global options used for HTTP client #include #include Reboot system on kernel panic Automatic reboot into previous running image on upgrade failure u32:1-30 Timeout before automatic reboot (minutes) Timeout out of range, must be 5 to 30 minutes Global options used for SSH client #include #include plays sound via system speaker when you can login Enable root partition auto-extention on system boot System time-format 12-hour 24-hour 12-hour 12 hour time format 24-hour 24 hour time format (12-hour|24-hour) 12-hour Disable autosuspend for all USB devices