sap_hana_preconfigure: Boot command line not updated on RHEL 9.3 and later when using grub2-mkconfig

[berndfinger]

Ansible Role

sap_hana_preconfigure

OS Family

RHEL

Ansible Controller - Python version

Python 3.13.5

Ansible-core version

ansible [core 2.18.6]

Bug Description

When running the role sap_hana_preconfigure with parameter sap_hana_preconfigure_modify_grub_cmdline_linux set to true, the entries processor.max_cstate=1 intel_idle.max_cstate=1 are added to kernelopts in /boot/grub2/grub.cfg and also but after a reboot, these two options are not active (=are not contained in /proc/cmdline).

This behavior is described in https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/9.3_release_notes/new-features#new-features-boot-loader.

Fix: Run grub2-mkconfig -o /boot/grub2/grub.cfg --update-bls-cmdline on RHEL systems of version 9.3 and later.

Bug reproduction

1. Run the role sap_hana_preconfigure with parameter sap_hana_preconfigure_modify_grub_cmdline_linux set to true.
2. Reboot the managed node if not already done by the role.
3. Log in to the managed node and run:
   # cat /proc/cmdline
4. Observe that the entries processor.max_cstate=1 intel_idle.max_cstate=1 are not part of the output.

Community participation

Happy to implement this bug fix

[berndfinger]

Maybe we should use this opportunity to switch to grubby for RHEL 8 and later anyway.

[berndfinger]

The role sap_general_preconfigure is also using grub2-mkconfig.

[marcelmamula]

Both SLES 15 and 16 use grub2-mkconfig so you might have to do same conditional for os_family as for UEFI in handler.

Same happened with LSR selinux role where they switched to grubby so we will have to change it in future.

[berndfinger]

Overview of handlers in preconfigure roles:
sap_general_preconfigure:

• __sap_general_preconfigure_regenerate_grub2_conf_handler
  • Called from: tasks/RedHat/installation.yml, task Call Reboot handler if necessary
  • Called from: tasks/SLES/generic/grub_update.yml, task Trigger grub update if necessary
• __sap_general_preconfigure_reboot_handler
  • Called from handlers/main.yml, tasks:
    • Run grub-mkconfig (BIOS mode)
    • Run grub-mkconfig (UEFI mode)
  • Called from tasks/SLES/installation.yml, task Call Reboot handler if necessary
  • Called from tasks/RedHat/generic/configure-selinux.yml, tasks:
    • Set SELinux state to '{{ sap_general_preconfigure_selinux_state }}' in /etc/selinux/config
    • Set SELinux type to 'targeted' in /etc/selinux/config
    • SELinux - Call Reboot handler if necessary
    • Disable SELinux also on the kernel command line, RHEL >= 8
    • Make sure SELinux is not disabled on the kernel command line, RHEL >= 8
• __sap_general_preconfigure_packagekit_handler
  • Called from: tasks/SLES/installation.yml, task Mask packagekit.service when present
• __sap_general_preconfigure_mount_tmpfs_handler
  • Called from: tasks/RedHat/generic/configure-tmpfs.yml, tasks:
    • Configure tmpfs in /etc/fstab
    • Trigger remounting if /dev/shm has not the expected size

sap_netweaver_preconfigure:

• __sap_netweaver_preconfigure_regenerate_grub2_conf_handler:
  • Called from tasks/SLES/generic/grub_update.yml, task Trigger grub update if necessary
• __sap_netweaver_preconfigure_reboot_handler
  • Called from handlers/main.yml, tasks
    • Run grub-mkconfig (BIOS mode)
    • Run grub-mkconfig (UEFI mode)
  • Called from tasks/SLES/installation.yml, task Call Reboot handler if necessary
• __sap_netweaver_preconfigure_packagekit_handler
  • Called from: tasks/SLES/installation.yml, task Mask packagekit.service when present

sap_hana_preconfigure:

• __sap_hana_preconfigure_regenerate_grub2_conf_handler
  • Called from: tasks/RedHat/generic/configure-c-states-for-lower-latency.yml, task Configure C-States for lower latency
  • Called from: tasks/RedHat/generic/disable-thp.yml, task Disable transparent hugepages at boot time
  • Called from: tasks/SLES/generic/grub_update.yml, task Trigger grub update if necessary
• __sap_hana_preconfigure_grubby_update_handler
  • Called from: tasks/RedHat/generic/enable-tsx.yml, task Enable TSX at boot time
• __sap_hana_preconfigure_grubby_thp_handler
  • Called from: tasks/RedHat/generic/configure-thp.yml, task Set THP to '{{ __sap_hana_preconfigure_fact_thp }}' at boot time
• __sap_hana_preconfigure_reboot_handler
  • Called from handlers/main.yml, tasks
    • Run grub-mkconfig (BIOS mode)
    • Run grub-mkconfig (UEFI mode)
  • Called from tasks/SLES/installation.yml, task Call Reboot handler if necessary
• __sap_hana_preconfigure_packagekit_handler
  • Called from: tasks/SLES/installation.yml, task Mask packagekit.service when present

[berndfinger]

Fixed in #1083.

[kksat]

@berndfinger just out of curiosity any particular reason not to use bootloader role from linux-system-roles? https://github.com/linux-system-roles/bootloader Looks like it can do what is required here

[marcelmamula]

@kksat It cannot be used because at beginning of this year they removed compatible code grub2-mkconfig and replaced it with grubby, which is not working on SLES. My colleague is working on updating LSR role to allow OS specific workflow.