Questions tagged [grub2]

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

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63
votes
4answers
168k views

How do I update GRUB in Arch Linux

In Ubuntu, we use this command to update GRUB: # update-grub But how do I update GRUB version 2.00 in Arch Linux?
56
votes
2answers
56k views

How to know if I'm booting using UEFI?

I was searching, but didn't find an obvious way to know if GRUB is using UEFI in the system boot, or the BIOS compatibility mode, or a full fledged BIOS. I found only Windows methods. Is there ...
52
votes
6answers
68k views

Why does Linux allow ‘init=/bin/bash’?

I recently found out that if I edit GRUB before booting and I add rw init=/bin/bash I end up with a root shell. Being in a condition that I want to understand everything I would like to know why this ...
41
votes
16answers
262k views

GRUB starts in command line after reboot

I installed Linux Mint on my laptop along with a pre-installed Windows 10. When I turn on the computer, the normal GRUB menu appears most of the time: But after booting either Linux or Windows then ...
40
votes
10answers
65k views

How can I tell GRUB I want to reboot into Windows—before I reboot?

I have a dual boot Linux/windows system set up, and frequently switch from one to the other. I was thinking if I could add a menu item in one of the menus to reboot directly into windows, without ...
40
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5answers
63k views

Can GRUB font size be customised?

I would like to reduce the size of the font of GRUB boot loader. Is it possible and so how?
35
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3answers
89k views

“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 ...
33
votes
7answers
7k views

Why do most distributions chain UEFI and grub?

Most distributions install a additional boot loader on an UEFI system. UEFI itself is a boot loader, it offers a menu to select different operating systems or individual kernels. Furthermore, the UEFI ...
32
votes
3answers
57k views

Debian/Grub2: Moving root partition to new drive?

Does anybody have a suggestion for how to move the root partition to a new drive and set up grub2 to boot on that drive? I seem to have no luck instructing grub-mkconfig what it is I want to do (e.g. ...
31
votes
1answer
46k views

Can GRUB2 share the EFI system partition with Windows?

I have an existing Windows 7 GPT installation, which already has a EFI System partition. I am now trying to install a Linux on a separate harddisk, which is also GPT formatted. I did not find any ...
30
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4answers
55k views

Installing Grub 2 on a USB flash drive

MultiBootISOs is a tool that let you install Grub on a USB flash drive. I really like it because it lets me boot from ISO files and let me put a bunch of ISOs on my USB and choose which one to boot. ...
28
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4answers
28k views

Is GRUB the best bootloading solution? Is there an easier alternative?

I have had some rather bad experiences with GRUB2. I could say (and have said) some nasty things about its design and development process. I especially dislike its means of update: for whatever reason ...
27
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2answers
334k views

Recovering from 'grub rescue>' crash [closed]

Originally posted to AskUbuntu.com ... AskUbuntu has adopted a policy of closing questions about EOL (End Of Life) versions. There's a vocal contingent to remove them as well. To prevent ...
27
votes
10answers
69k views

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 /...
23
votes
4answers
79k views

Windows boot option is missing after installing CentOS 7, how can I get it back?

I recently installed CentOS 7 on a machine that has been running Windows 7. I did a dual boot installation and installed CentOS in a partition. But when I boot up my machine, it only gives me two ...
22
votes
5answers
52k views

What is the difference between LILO and GRUB?

I am running a web server under Debian and I currently have GRUB installed. Should I consider using LILO instead of GRUB? And what are the advantages of each?
22
votes
6answers
36k views

How can I prevent Windows from overwriting GRUB when using a dual-boot machine

I've been reading a lot about dual-booting, and it seems as easy as loading Windows and then loading Linux with GRUB, but everybody says that Windows loves to trash GRUB when it gets the opportunity. ...
22
votes
1answer
62k views

Arch Linux grub installation error “airootfs”

I was following the official installation tutorial. Everything was smooth until the boot loader section. I had encountered the error of /usr/bin/grub-probe: error: failed to get canonical path of '...
21
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3answers
66k views

How to correctly install GRUB on a soft RAID 1?

In my setup, I have two disks that are each formatted in the following way: (GPT) 1) 1MB BIOS_BOOT 2) 300MB LINUX_RAID 3) * LINUX_RAID The boot partitions are mapped in /dev/md0, the ...
20
votes
8answers
117k views

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/...
18
votes
5answers
32k views

Arch GRUB asking for /run/lvm/lvmetad.socket on a non lvm disk

I am running this script based on the ArchWiki setup procedure. It fails on the GRUB configuration step I am using the archlinux-2013.12.01-dual.iso inside VMware Player with 1 GB ram, sda is 810 MB....
18
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2answers
36k views

How to check on which drives grub2 has actually installed an MBR?

I'm on a Debian/Squeeze system (with a history going back to at least Woody) which was upgraded to grub2 as part of the Squeeze upgrade. All works well, but I'm about to mess with the disk ...
18
votes
3answers
4k views

How should I configure grub for booting linux kernel from a USB hard drive?

I have a laptop hard drive in an external enclosure which I use as a large pendrive. For an added twist, I have installed Linux on it, so I can boot any machine with my distribution of choice (e.g. ...
18
votes
3answers
4k views

FreeNAS grub2 booting ISO

I've got usb-keys setup to multi-boot different Linux images. I wouldn't mind adding FreeNAS, and there's a doc with samples to add to grub.cfg menuentry "FreeNAS-8.0.4-RELEASE-x64" { insmod ufs2 ...
17
votes
4answers
23k views

arch linux- error:failed to get canonical path of 'airootfs' (grub to USB installation)

I'm trying to install arch-linux for the first time. everything was OK till I tried to install "grub" boot-loader to a USB drive. I am working by the WIKI ARCH LINUX guide. both of this commands ...
17
votes
2answers
61k views

GRUB2 and kernel vga= parameter

According to the documentation, use of the vga= kernel parameter is deprecated as of GRUB2. The fact that some newer kernels don't seem to support it anymore on certain adapters is of no concern as ...
17
votes
5answers
109k views

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 ...
17
votes
5answers
58k views

Enabling IOMMU in the kernel for graphics card pass-through

Short question: How can I turn on the intel_iommu setting in the Linux kernel? I run a Debian host, using the grub2 bootloader. Documentation I've seen says to edit /boot/grub/menu.lst, which seems ...
16
votes
1answer
10k views

mistakenly deleted /boot folder and rebooted

I mistakenly deleted the /boot folder from my filesystem, rebooted, and all I get now is this: error: file '/boot/grub/i368-pc/linux.mod' not found. grub rescue>
16
votes
1answer
22k views

grub-install : File descriptor 3 leaked on vgs invocation

I installed Debian Jessie on a LVM in a software RAID 1. To make sure MBR are written on both disks of the RAID 1, I run dpkg-reconfigure grub-pc (as suggested here) and select both disks. I get ...
16
votes
1answer
14k views

Where can I learn more about how to use the GRUB `ntldr` command (module?)

I recently stumbled across the GRUB ntldr module. Apparently one of the things it can be used for is as an alternative to chainloader to boot the NT >= 6.0 versions of Windows as in the example below....
15
votes
2answers
3k views

How do I use the TPM to seal away data on an UEFI booted system?

I would like to seal away files on my system using keys stored in the TPM. Since my system uses UEFI to boot, I can no longer use TrustedGrub as a boot loader to maintain my trust chain. Are there any ...
14
votes
5answers
2k views

Why is drive/partition number still used?

Many times, especially when messing around with boot-loaders, I'll see numerical drive and partition numbers used. For instance, in my /boot/grub/grub.cfg I see set root='hd0,gpt2', my UEFI boot ...
14
votes
3answers
35k views

Grub installation failed

I had a good running installation of Debian Jessie, but then I ran apt-get update && apt-get upgrade && apt-get dist-upgrade. And then after rebooting, it came directly to the BIOS. I ...
14
votes
3answers
15k views

Arch linux : pacman does not work when chrooting

I have Ubuntu installed on my computer. I decided to install Arch linux, but I skipped the part about Grub installation as it is already installed. Seeing that Arch does not show up in Grub's menu ...
14
votes
3answers
8k views

Chainload two Grub2 installations

This is really getting me down. I have Gentoo and Ubuntu, both with Grub2. Gentoo has a dedicated /boot partition, while Ubuntu does not. I have a menuentry in Gentoo's /etc/grub.d/40_custom to boot ...
13
votes
1answer
15k views

GRUB_CMDLINE_LINUX_DEFAULT vs GRUB_CMDLINE_LINUX

What is the difference between these two options in /boot/default/grub GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" GRUB_CMDLINE_LINUX=""
12
votes
2answers
16k views

Is Grub installed to all the MBR of a RAID array by default by the Debian Installer?

If I use the Debian Stable (Squeeze) Installer to install Debian, booting from a RAID1 pair of drives, does it write grub to the MBR of both drives - if not, how should I best protect against a drive ...
11
votes
2answers
77k views

How Do You Pass VGA/VESA Modes with GRUB2?

One of my machines has a 3 TB HD setup to triple boot into Mint 14 (Ubuntu 12.10 variant), Slackware 14.1 and Arch Linux. The HD is formatted using the GPT/Guid system. The Grub2 technically "belongs" ...
11
votes
6answers
28k views

Add FreeBSD to GRUB2 boot menu

I have Gentoo x64 installed with Grub2 on my MBR drive. Today I installed FreeBSD x64 9.2. Now I'm in Gentoo and trying to add FreeBSD to grub2 menu list. grub2-install /dev/sda os-prober grub2-...
11
votes
6answers
43k views

Installed Centos 7 after Windows and can't boot into CentOS

I wanted to setup a dual boot for Windows 7 and CentOS 7 I had a Windows 7 machine with 500GB disk. I shrank the Windows partition to provide space for CentOS 7 (roughly 230GB). I created a USB ...
11
votes
1answer
13k views

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 ...
11
votes
2answers
12k views

GRUB2: how to remember grub last choice

I'm currently trying out various distros so when I boot up my laptop I have several OS to choose from. Usually, all those distros install grub2 and locate themselves at the top of the list so they're ...
11
votes
5answers
45k views

GRUB2: boot to a second (another) hard disk

I have researched for this question, but have not been able to find a clear answer... or even a clear question. So I will use a simple example. My computer have **two hard disks: ** Hard Disk 1: ...
11
votes
2answers
8k views

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]] [--...
11
votes
2answers
4k views

Moving /boot partition without messing up the system

I have deleted my old Linux Mint partition I had installed beside my new current Rafaela one. Thus, I have free space I want to add to my home partition. Above you can see the partition layout: sda4 ...
11
votes
1answer
473 views

Where in GRUB2 source code is the handover/jump to kernel code?

I'm looking for the line of code where GRUB2 finally jumps to kernel code and thus hands over execution on x86 systems? I guess it's in an assembler file since this is very low architecture stuff. I ...
10
votes
1answer
992 views

In Debian, which package is responsible for creation of /etc/default/grub?

There are many packages which have grub in their names and part of the GRUB (the Grand Unified Boot Loader). The ones which are installed on my system are - grub-common grub-emu grub-pc grub-pc-...
10
votes
1answer
23k views

GRUB and LILO both fail to install to NVMe hard disk when installing Debian

I'm trying to install 64-bit Debian stable on a Lenovo Thinkpad. When I get to the installation step that installs the bootloader, I get this message: An installation step failed. You can try ...
10
votes
2answers
502 views

What are these commands for?

Yesterday I had to install a Windows with its Grub override. Well, it's not the first time I had to fix Grub, so I used LiveCD, mounted the root partition (I don't have boot, just / and home) and ran ...

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