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 ...
24
votes
3answers
25k 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. ...
21
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3answers
34k 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. ...
18
votes
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 ...
17
votes
1answer
16k 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 ...
16
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4answers
10k 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 ...
15
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5answers
22k 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?
13
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1answer
1k 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
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5answers
703 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 ...
13
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3answers
5k 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 ...
12
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1answer
6k 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 ...
12
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0answers
297 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 ...
11
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5answers
27k 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 ...
10
votes
2answers
10k 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?
10
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2answers
446 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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7answers
8k 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 ...
9
votes
4answers
2k 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 ...
9
votes
2answers
15k 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 ...
9
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2answers
10k 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 ...
9
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1answer
18k views

How do I update grub in Arch Linux

In Ubuntu we use below command to update grub 0.98 : # update-grub But how do I update grub version 2.00 in Arch Linux ? `
9
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1answer
5k views

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
9k views

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
7k views

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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3answers
4k views

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 ...
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4answers
8k views

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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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. ...
8
votes
1answer
187 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 ...
7
votes
5answers
9k 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 ...
7
votes
4answers
23k 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 ...
7
votes
1answer
2k views

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 ...
7
votes
1answer
8k 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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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
votes
2answers
420 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
votes
1answer
378 views

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
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2answers
698 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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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 ...
6
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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 ...
6
votes
1answer
363 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
votes
1answer
148 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
votes
2answers
3k views

Grub 'incompatible license' error

The other day, I was using a laptop for general desktop use when its keyboard began to act up. Most of the keys on the keyboard's right side stopped working entirely and key combinations such as Ctrlu ...
6
votes
2answers
6k 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 ...
6
votes
4answers
840 views

Is there an easier way to manipulate GRUB 2 entries?

Using GRUB 2 is harder than GRUB 1 for these use cases: It looks like if I want to reorder GRUB 2 menu entries appear in the selection window, I have to rename the files in "/etc/grub.d/" directory. ...
6
votes
1answer
2k views

EFI boot to Linux on a MacBook Pro

8,3 MacBook Pro 2011, running Ubuntu 11.10 amd64. Here's the situation. Screen backlight and a few other things only work if booting in EFI, so I need to boot Ubuntu in EFI to get things working. ...
6
votes
0answers
3k 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 ...
6
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2answers
1k views

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 ...
5
votes
5answers
856 views

Bootstrapping a DSL installation onto a machine with no BIOS boot support

I have a vintage 2001 laptop (Vaio R505) which is very hardware limited. Fortunately there is much that works, but I can't figure how to make it work better. The two biggest constraints are 256MB RAM ...
5
votes
3answers
6k views

How to make grub work again after drive reassignment?

My config: opensuse 11.4, boot partition at pendrive and hard drives with partitions sda1, sda2, sdb1. Today I changed chassis for my computer, and by mistake I attached second drive to SATA 3 ...
5
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4answers
7k views

Grub error 15 (file not found)

I'm trying to fix a problem with a new installation. I'm running this existing distro (Ubuntu) from /dev/sdb with a new OS, Gentoo, installed on /dev/sda. I'm glad I took the trouble of setting these ...
5
votes
2answers
4k views

How to recreate EFI boot partition?

I've installed Fedora on my machine with / partition, swap partition and ESP partition for EFI booting. Now, I was installing Elementary OS instead of Fedora. I have formatted the / partition ...
5
votes
1answer
2k views

Choose at GRUB menu whether NVidia driver should be used

For some games, I need the nvidia-current driver, but when it's enabled, I can't get my work done as it messes up everything. So is there a way I can get two options in my GRUB menu? One wich will ...