Boot Loader Configuration
One objective, and the last of the 62. RHEL 10 uses Boot Loader Specification entries, so grub.cfg no longer lists kernels and grubby is the tool. The capture backs up every boot file before touching anything, because a broken bootloader is the only mistake on this exam that a running machine cannot show you.
Deploy and Maintain Guide 47 of 67 Advanced
- OSRHEL 10.0
- Kernel6.12.0-55.9.1.el10_0
- dnf4.20.0
- Flatpak1.16.0
- TimeAbout 15 min
With GRUB_ENABLE_BLSCFG=true - the RHEL default - each kernel is a file in /boot/loader/entries/. grub.cfg contains a blscfg directive and no kernel entries, so regenerating it does not change kernel arguments, and material that tells you to edit grub.cfg directly predates this.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| RHCSA-A01 | 192.168.0.31 | RHEL 10.0 | Practice node (graded) - spare /dev/sda | 2 Core | 4 GB | 50 GB + 15 GB |
This guide includes
Use this for the last of the 62 objectives. This matters because BLS changed where kernel entries live - so grub.cfg is no longer the file you edit, and arguments are managed per entry instead.
- reading what the bootloader is actually made of
- finding why BLS makes
grub.cfgboring now - listing the kernels, and choosing one
- adding a kernel argument, then removing it, with the targeting flags
- editing the defaults file, and regenerating
Before you start
- A sudo-capable account.
- The session backs up
grub.cfg, the BLS entries and/etc/default/grub, and restores all three. Verify a backup exists before doing any of this on a machine you care about.
-
What the bootloader is made of
-
BLS is why `grub.cfg` is boring now
-
Listing and choosing a kernel
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Adding a kernel argument
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Removing it, and the targeting flags
-
The defaults file, and regenerating