Which file is the configuration file that GRUB 2 generates, and which administrators are told not to edit by hand on a typical Linux distribution?
LPIC-1 Exam 101-500, objective 102. Linux installation and package management easy
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How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct /boot/grub/grub.cfg
Correct. GRUB 2 writes this file from the settings in /etc/default/grub and the scripts in /etc/grub.d/, and overwrites it on the next regeneration, which is why hand edits do not survive.
Not correct /boot/grub/menu.lst
Wrong for GRUB 2. menu.lst is the GRUB Legacy (GRUB 0.97) menu file, and that one was edited by hand.
Not correct /etc/default/grub
Wrong. This is an input, not the output: it holds shell-style variables such as GRUB_TIMEOUT and GRUB_CMDLINE_LINUX and you are expected to edit it.
Not correct /etc/grub.d/40_custom
Wrong, though also an input. This is the script where you add your own menu entries; its contents get copied into grub.cfg when the configuration is regenerated.
Why
GRUB 2 splits configuration into editable inputs and a generated output. You edit /etc/default/grub and the scripts under /etc/grub.d/, then regenerate /boot/grub/grub.cfg. GRUB Legacy had no generation step: /boot/grub/menu.lst (sometimes reachable as grub.conf) was the hand-maintained file.
Where this comes from
- Cited
- LPI exam objective 102.2
- What it says
- GRUB 2 configuration is generated into grub.cfg from /etc/default/grub and /etc/grub.d.
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 102 and space the ones you get wrong.
More questions on this objective
- A mail server keeps filling its root filesystem because spooled mail and logs grow without bound, and when the disk fills the whole system becomes unusable. Which single change to the disk layout most directly contains that failure? machine-checked
- In LVM terminology, which object is created directly on a partition or whole disk so that its storage can be added to a pool? machine-checked
- You are laying out storage for a general-purpose Linux server. Which TWO of the following are genuine reasons to use LVM for the data filesystems rather than plain partitions? machine-checked
- You replaced the boot disk in a BIOS/MBR system and need to write the GRUB 2 boot loader into the master boot record of /dev/sda, installing the required GRUB modules under /boot. Which command does that? machine-checked
- On a GRUB 2 system whose configuration file is /boot/grub/grub.cfg, type the grub-mkconfig command — including the option and its argument — that regenerates that file. machine-checked
- A GRUB menu entry ends with the directives 'set root=(hd0,3)' followed by 'chainloader +1'. What is GRUB doing? machine-checked