GRUB - Grand Unified Boot Loader

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GrubGRUBs responsibility in the boot process

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GRUB Configuration Options

Grub optionsThere are configured2 directories to note when talking about GRUB;

/etc/grub - This directory stores configuration scripts that define boot entries for GRUB2.

/boot/grub - This directory stores the actual GRUB2 configuration files used during boot.

There are also 2 commands to note for GRUB configuration:

grubby

• Function: grubby is a command-line tool that allows you to directly manipulate individual GRUB2 menu entries on your system. It provides functionalities for:

  • Setting the default boot entry
  • Adding, removing, or modifying existing entries
  • Changing boot order
  • Viewing information about current entries

• Focus: grubby operates on individual boot entries within /boot/grub2/grubenvthe existing GRUB2 configuration.

  resume 

grub2-mkconfig

• Function: grub2-mkconfig (rarelyor used)sometimes -shortened essentiallyto forupdate-grub systemson withsome systems) is a 'sleep mode' - not really everutility used onto servers,regenerate morethe ofGRUB2 aconfiguration desktop feature.

  rhgbfile (rarelygrub.cfg) used)located -in graphical/boot/grub. bootIt screen,reads ratherconfiguration thanscripts textfrom -the not/etc/grub.d reallydirectory.

ever
• Focus: usedgrub2-mkconfig focuses on a server, more of a desktop feature.

  quiet (rarely used) - hidesrebuilding the bootentire outputGRUB2 whenconfiguration bootingfile a system up - not really ever usedbased on athe server,defined morescripts. ofThis a desktop feature.

  Grub options can be changed usingensures the grubbygrub.cfg command

  file

  removereflects rhgbany feature for all kernels installed

  grubby --update=ALL --remove-args="rhgb"

  Changeschanges made using grubby modifyto the grubenvconfiguration file, whichscripts in turn/etc/grub.d.

alters

the kernel files stored in /boot/loader/entries

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