CentOS/Grub - Revision history

Kenneth: /* performance tweaks */

2026-01-27T02:02:26Z

performance tweaks

← Older revision		Revision as of 02:02, 27 January 2026
Line 78:		Line 78:
	GRUB_TIMEOUT=60		GRUB_TIMEOUT=60
	GRUB_DEFAULT=saved		GRUB_DEFAULT=saved
			GRUB_SAVEDEFAULT=true
	GRUB_DISABLE_SUBMENU=true		GRUB_DISABLE_SUBMENU=true
	GRUB_TERMINAL_OUTPUT="console"		GRUB_TERMINAL_OUTPUT="console"

Kenneth: /* performance tweaks */

2026-01-27T02:02:08Z

performance tweaks

@@ Line 58: / Line 58: @@
 done
 </pre>
 == performance tweaks ==

Kenneth: /* Example */

2026-01-27T01:59:27Z

Example

← Older revision		Revision as of 01:59, 27 January 2026
Line 46:		Line 46:
	# grub2-mkconfig -o /boot/grub2/grub.cfg		# grub2-mkconfig -o /boot/grub2/grub.cfg
	Generating grub configuration file ...		Generating grub configuration file ...
			Adding boot menu entry for UEFI Firmware Settings ...
			done
			</pre>

			<pre>
			# grub2-mkconfig -o /etc/grub2-efi.cfg
			Generating grub configuration file ...
			Found Windows Boot Manager on /dev/sdb1@/efi/Microsoft/Boot/bootmgfw.efi
			Found Ubuntu 24.04.1 LTS (24.04) on /dev/sdb5
	Adding boot menu entry for UEFI Firmware Settings ...		Adding boot menu entry for UEFI Firmware Settings ...
	done		done

Kenneth: /* Generate Grub Config */

2026-01-26T04:08:39Z

Generate Grub Config

← Older revision		Revision as of 04:08, 26 January 2026
Line 8:		Line 8:
	# OR		# OR
	grub2-mkconfig -o /boot/grub2/grub.cfg		grub2-mkconfig -o /boot/grub2/grub.cfg
			# OR
			grub2-mkconfig -o "$(readlink -e /etc/grub2.cfg)"

	# ls -la /etc/grub2.cfg		# ls -la /etc/grub2.cfg
Line 17:		Line 19:
	# It is automatically generated by grub2-mkconfig using templates		# It is automatically generated by grub2-mkconfig using templates
	# from /etc/grub.d and settings from /etc/default/grub		# from /etc/grub.d and settings from /etc/default/grub

			-

			Note, I like this version: <ref>https://unix.stackexchange.com/questions/152222/what-is-the-equivalent-of-update-grub-for-rhel-fedora-and-centos-systems</ref>
			grub2-mkconfig -o "$(readlink -e /etc/grub2.conf)"
			better than this, because if the file doesn't exist, it will dump it to the screen, instead of creating a file
			grub2-mkconfig -o $(readlink -f /etc/grub2.conf)

	=== Example ===		=== Example ===

Kenneth: /* = Example */

2026-01-24T22:06:46Z

= Example

← Older revision		Revision as of 22:06, 24 January 2026
Line 18:		Line 18:
	# from /etc/grub.d and settings from /etc/default/grub		# from /etc/grub.d and settings from /etc/default/grub

	=== Example ==		=== Example ===

	<pre>		<pre>
Line 40:		Line 40:
	done		done
	</pre>		</pre>


	== performance tweaks ==		== performance tweaks ==

Kenneth at 22:06, 24 January 2026

2026-01-24T22:06:34Z

@@ Line 1: / Line 1: @@
   grub2-mkconfig -o /boot/grub2/grub.cfg
 <pre>
@@ Line 9: / Line 41: @@
 </pre>
 performance tweaks
 /etc/default/grub
 <pre>
@@ Line 31: / Line 65: @@
 GRUB_DISABLE_RECOVERY="true"
 </pre>

Kenneth: Created page with " grub2-mkconfig -o /boot/grub2/grub.cfg

 # grub2-mkconfig -o /boot/grub2/grub.cfg Generating grub configuration file ... Adding boot menu entry for UEFI Firmware Settings ... done

performance tweaks /etc/default/grub

 # vim grub GRUB_TIMEOUT=60 GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console"  #GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash selinux=0"  #GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash intel_pst..."

2026-01-24T21:59:39Z

Created page with " grub2-mkconfig -o /boot/grub2/grub.cfg <pre> # grub2-mkconfig -o /boot/grub2/grub.cfg Generating grub configuration file ... Adding boot menu entry for UEFI Firmware Settings ... done </pre> performance tweaks /etc/default/grub <pre> # vim grub GRUB_TIMEOUT=60 GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" #GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash selinux=0" #GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash intel_pst..."

New page

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

<pre>
# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Adding boot menu entry for UEFI Firmware Settings ...
done
</pre>

performance tweaks
/etc/default/grub
<pre>
# vim grub
GRUB_TIMEOUT=60
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"

#GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash selinux=0"

#GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash intel_pstate=disable pcie_aspm.policy=performance pci=pcie_b
us_perf noibrs noibpb nopti nospectre_v2 nospectre_v1 l1tf=off nospec_store_bypass_disable no_stf_barrier mds=off mi
tigations=off intel_idle.max_cstate=0 idle=poll transparent_hugepage=never audit=0 selinux=0 nmi_watchdog=0 nohz=on
clocksource=tsc nosoftlockup mce=ignore_ce cpuidle.off=1 skew_tick=1 processor.max_cstate=0 acpi_irq_nobalance"

GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet splash intel_pstate=disable pcie_aspm.policy=performance pci=pcie_bu
s_perf noibrs noibpb nopti nospectre_v2 nospectre_v1 l1tf=off nospec_store_bypass_disable no_stf_barrier mds=off mit
igations=off intel_idle.max_cstate=0 idle=poll transparent_hugepage=never audit=0 selinux=0"

GRUB_DISABLE_RECOVERY="true"
</pre>