Unix and Linux Stack Exchange
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Questions tagged [grub2]

GRUB2 is the second revision of the GRand Unified Bootloader, with versions numbered 1.9x and 2.yz.

GNU GRUB (GRand Unified Bootloader) is a bootloader. It was originally intended as a common bootloader for various new operating systems conforming to the multiboot specification. Nowadays, many Linux distributions have adopted GRUB as their default bootloader.

There are two major versions of GRUB, with incompatible configuration files:

  • GRUB Legacy, with version numbers up to 0.97;
  • GRUB 2, with version numbers from 1.9x to 2.yz.

This tag is about GRUB 2. Note that versions numbered 1.9x are GRUB 2, not GRUB Legacy.

GRUB partly resides in the master boot record, so it is launched by the BIOS. GRUB2 supports both legacy BIOS and UEFI. It is able to read most filesystems, and its main job is to read the kernel and initramfs from a disk in order to place them into memory and launch the kernel.

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1768 questions
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"warning: File system `ext2' doesn't support embedding." but my system isn't embedded either, why is grub trying?

I'm reading myself for the release of Jessie on Debian, so I'm extra cautious (should be said paranoid) about any message that can cause problems, namely warnings. My system is a desktop with Debian testing/unstable installed, on ext4 partitions for…
Braiam
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How to correctly set up the right GRUB 2 default menu entry?

I'm running GRUB 2.00 on a Gentoo Linux system. I compile my own kernels manually, and then I install them in /boot with make install. I have the following kernels in /boot at the moment: # ls -1…
user22304
28
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6 answers

grub-probe: error: failed to get canonical path of /cow

I'm trying to re-install grub from a USB drive. I run the following: sudo mount /dev/sda6 /mnt sudo grub-install --root-directory=/mnt /dev/sda I get the following error: grub-probe: error: failed to get canonical path of /cow. can someone explain…
elyashiv
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7 answers

Grub error: file '/grub/i386-pc/normal.mod' not found?

I recently install arch (hopefully successfully) on my machine. When I went to reboot however I had a problem. I got a black screen with text saying Grub loading. Welcome to GRUB! error: file '/grub/i386-pc/normal.mod' not found. Entering rescue…
Griffin
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How to preview my GRUB menu without rebooting?

I want to change my default boot OS in GRUB2. But the only way I know of seeing the order of the OS I want in the GRUB menu is doing a reboot and seeing the menu displayed. In grub.cfg there are many more menuentry lines than actual choices in the…
ARX
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16
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2 answers

What does the --hint option in grub2's search command do?

I'm looking at the official GRUB2 docs for the search command, as found on http://www.gnu.org/software/grub/manual/grub.html#index-search Command: search [--file|--label|--fs-uuid] [--set [var]] [--no-floppy] name Search devices by file (-f,…
Jens
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14
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1 answer

Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported

I have noticed that since some time ago, the following warning message appears when updating grub: Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported. cat /etc/default/grub lists the…
Vlastimil Burián
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14
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1 answer

Grub2 encryption reprompt

Whenever I accidentally make an error entering my password to decrypt my disks grub drops me into the resuce shell. Is there a way to have it so that grub just asks me to try again? Similarly to how the kernel does it with an unencrypted /boot. If…
Scoopta
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14
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1 answer

Grub with retina displays (high resolution)

I currently use Ubuntu on my macbook pro with grub. My macbook has a retina display with 2560x1600 resolution. The grub startup screen font is so tiny that it is barely readable. How can I make grub appear in an eye-friendly way with this…
binaryanomaly
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4 answers

How do I hide grub boot menu unless shift is pressed?

I've read the forum but it seems my grub boot menu doesn't follow the form of the config file. I would like the menu to not appear unless Shift is pressed. My grub menu appears every boot and stays there until you select a menu item. My current…
wkdmarty
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2 answers

Is it possible to set the screen resolution from inside the GRUB terminal?

When inside the GRUB2 screen, if you hit C you are taken to console mode. Is it possible from that console to set the screen resolution. Note: I know it can be changed in the grub config. I want to know if there is a command you can type in to…
Mark
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9
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1 answer

Looking for the right way to rename the GRUB boot entries

I am taking about the naming of existing/default GRUB boot entry. Currently I've the following options at GRUB screen: Trisquel GNU/Linux Advanced options for Trisquel GNU/Linux Trisquel GNU/Linux, with Linux-Libre 3.13.0-39-lowlatency (recovery…
Pandya
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9
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2 answers

What is `$menuentry_id_option` in grub?

I was fiddling with my GRUB 2 config files (/boot/grub/grub.cfg) and I noticed that the menuentry line for the automatically added Ubuntu boot looks like this: menuentry 'Ubuntu 14.04 Trusty Tahr (on sda5)' --class ubuntu --class gnu-linux --class…
Robin
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7
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2 answers

Background image manual grub.cfg

I'm trying to manually install a background image for grub on a bootable flash drive. Since the drive only boots ISO's and has no installed OS, I can't take advantage of scripts such as update-grub to do this for me and the posts regarding editing…
Elder Geek
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Set which grub loader to use after dual booting two linux OSes

I installed a second Linux distro recently which replaced the old grub that was already in place with its own fresh installation. I would like keep using the grub loader from the first OS, Ubuntu.
Nicolas Martel
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