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

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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 ...
25
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3answers
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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. ...
25
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3answers
41k 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. ...
21
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1answer
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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 ...
21
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7answers
1k 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 ...
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3answers
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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 ...
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5answers
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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?
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5answers
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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 ...
17
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1answer
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How do I update grub in Arch Linux

In Ubuntu we use below command to update grub : # update-grub But how do I update grub version 2.00 in Arch Linux ? `
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2answers
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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 ...
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2answers
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How to know if I'm booting using UEFI

I was searching, but didn't found an obvious way to know if GRUB is using UEFI in the system boot, or the BIOS compatibility mode or a full fledged BIOS. Only Windows methods. Is there something in ...
15
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1answer
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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 ...
14
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7answers
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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 ...
13
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1answer
2k 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>
13
votes
4answers
7k 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 ...
13
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3answers
6k 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
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2answers
566 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 ...
12
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3answers
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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. ...
12
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5answers
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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 ...
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5answers
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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 ...
11
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2answers
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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 ...
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2answers
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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 ...
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2answers
14k 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?
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2answers
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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 ...
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5answers
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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 ...
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2answers
456 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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3answers
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How do I begin with building a Linux system from scratch?

I tried to make an operating system with my on custom built kernel. It didn't work out too well. I am using Ubuntu and have downloaded Linux 3.2.7 from kernel.org . I am not trying to change the ...
9
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2answers
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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 ...
9
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1answer
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grub error “superfluous RAID member” on update-grub

My system (wheezy/sid: 2.6.32-5-amd64 #1 SMP x86_64 GNU/Linux) is running fine - I'm just wondering what some messages mean. I have two mdraid arrays running up on my system. Here's cat /proc/mdstat: ...
9
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2answers
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How do I prevent GRUB from using/starting any graphical UI?

I have a problem with an older Laptop (Fujitsu Siemens LifeBook S6010, to be precise) and an Ubuntu (10.10, Xubuntu desktop) installation (fresh install). During installation the graphics hardware ...
9
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2answers
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Chainload syslinux from GRUB2 - show syslinux.cfg menu

I am using a Clonezilla live USB disk to reimage systems. In accordance to what is explained in ...
8
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1answer
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booting qemu/kvm directly from a file system

Having used Xen and its pygrub for a while, I'm now trying to do something similar with KVM/qemu. Basically, I have a LVM logical volume (though that could as well be a file) that contains the root ...
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4answers
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Poor TTY resolution with nVidia driver

The resolution of the TTY1-6 is poor ~ 640×480 Ubuntu 11.10 | Grub2 | nVidia | NVIDIA GT215 Board I went through the process on this site and after the edit the GRUB menu appears in the correct ...
8
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1answer
150 views

Is there any way to boot from iso while running system from live disk?

This is bit complicated question let me explain what is expected: I know that we can add GRUB menuentry with location of ISO file and boot from ISO using GRUB entry. (i.e this method) But suppose ...
8
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1answer
304 views

How to Pass High Resolution from GRUB2 to FreeBSD?

I boot FreeBSD-10-RELEASE from GRUB2. I have set up the GRUB2 boot menu to display very nicely at my laptop's max resolution of 1024x768x32. I know it's possible to pass this resolution to the boot ...
8
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1answer
2k views

Booting a file system image from a HDD using GRUB2 with persistence

How do I preserve changes I make to files when running an operating system that is booted - using GRUB2 - from a file that contains a file system. I managed to get GRUB2 to boot an image file that ...
7
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2answers
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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" ...
7
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3answers
334 views

GRUB confuses kernels/initramfs of Ubuntu and Arch Linux installation

I have a machine that used to dual-boot Ubuntu (16.04 currently) and Windows 7, with Ubuntu's GRUB as boot loader. Now I just added Arch Linux as third OS, following the official installation ...
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3answers
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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 ...
7
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1answer
9k views

How do I add PC BSD / FreeBSD to Grub 2 boot loader?

I have Ubuntu 10.04 installed as my primary operating system, and I installed PC BSD in a different partition: /dev/sda4 without installing it's boot loader. I figured out that I need to edit ...
7
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2answers
761 views

Installing other Linux in an encrypted disk

I recently got an SSD to replace my laptop's HDD and decided to change and use "full disk" encryption. I created a small unencrypted partition for /boot and an big encrypted LUKS partition where I ...
7
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1answer
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Can Grub2 multi-boot LUKS/LVM distros with only one boot partition?

There are many tutorials on the internet for multi-booting unencrypted distros using a single boot partition and chainloading. For example, booting 145 OSes. Likewise, there are tutorials for ...
7
votes
1answer
5k views

UEFI install (14.04) boots to GRUB command prompt, no GUI

I just installed zorin 9 core (14.04) on my Hard-Disk in UEFI mode. But, when I boot, all that comes up is a GRUB2 command line. I've searched for solution and came up with this command configfile ...
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2answers
823 views

Determine what program is in my MBR code

I've done a lot of partitioning / dual booting on my Macbook Pro. Right now I have Mac OS X installed along with Ubuntu 12.04, with Grub installed on the Ubuntu partition. I am wondering - what is ...
7
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2answers
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How can I boot the PC-BSD live DVD-ISO IMAGE directly via GRUB2?

Via the loopback command, GRUB2 allows to directly boot an ISO file. Now, I've configured the according menuentry to boot the PC-BSD Live DVD ISO, but when I try to boot it, the FreeBSD bootstrap ...
6
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2answers
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Ubuntu: How do the md devices get assembled at bootup?

How do the md devices get assembled at bootup in Ubuntu? Is /etc/mdadm/mdadm.conf truly the relevant factor here? My mdadm.conf is sound and I checked that while I was in the rescue CD environment. ...
6
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1answer
438 views

How can I prevent someone from gaining root access through the bootloader?

On Ubuntu 10.10 I can login as root without the root password by replacing ro quiet splash with rw init=/bin/bash. How can I secure my machine and disable this backdoor?
6
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1answer
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`Error: no such device…` after installing Arch Linux

I've seen many threads about this error but I couldn't find a solution. I've installed Arch Linux alongside Windows 8. (Dual Boot). I followed this video exactly but am getting the error below at ...
6
votes
1answer
248 views

What Linux kernel features does os-prober require to find a Windows 8 installation?

I built a new custom Linux kernel using make localmodconfig and after booting the new kernel, update-grub doesn't detect my Windows 8 installation. My distro kernel (with tons of modules I don't ...
6
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5answers
8k 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 ...