Questions tagged [grub2]

GRUB (GRand Unified Bootloader) is a bootloader package to load operating systems. GRUB2 is a rewrite, and the dominant version since 2009.

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How to recover from the GRUB losing its entries and faced with only "grub> _" at boot?

I performed a system upgrade from CentOS 7 to AlmaLinux 8 rather successfully (as noted here). During the process something strange happened and GRUB lost its boot entries entirely and my limited ...
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dpkg: error processing package linux-image-4.15.0-175-generic (/boot/grub/menu.lst not found)

I have this issue on Ubuntu 18.04 Server, probably because /boot/grub/menu.lst doesn't exist: root@myserver:~# apt install -f Reading package lists... Done Building dependency tree Reading ...
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How would I configure grub to skip the menu or set a timeout?

I was able to successfully configure PXE and pressed to get an entirely automated install running except for 1 issue: The GRUB menu pauses indefinitely until the user selects an option. I've got my ...
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Forgot grub2 password on Centos7 server

I forgot that I had a GRUB2 password set on my CentOS7 server. I have rebooted it and it is now prompting me for a password. Is there a way to bypass this password prompt, so that the server boots to ...
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Can you install GRUB on an MDADM Raid 1 device before it's added to the MD array?

So we have our 2 OS drives in a Raid 1 MDADM mirror. One of these drives has failed. Typically after replacing the failed drive, we do a sfdisk command to match the partition table, and then add the ...
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CentOS 8 / Red Hat / Rocky Linux - Blinking Cursor After Grub Menu - SAS RAID

Anyone have a solution for this slow boot: https://forums.centos.org/viewtopic.php?f=54&t=73569 Essentially: When I boot, my box posts fine, the Grub boot menu comes up, I select the first option, ...
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Tell Linux/GRUB to start iPXE on next boot?

I've just discovered the wonder that is iPXE. Im running various versions of Debian on many different computers, and would like to remotely tell them to reboot into iPXE, and have iPXE automatically ...
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How to prevent changes of GRUB_ENABLE_BLSCFG in /etc/default/grub

With Rocky Linux 8.4 (clone of RHEL 8.4) in /etc/default/grub I have GRUB_ENABLE_BLSCFG=false A “dnf update” that included grub2-tools changed it back to GRUB_ENABLE_BLSCFG=true Is there some way to ...
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Changing your kernel in AWS appears to break boot sequence (grub config issue?)

Using Ubuntu 20.04 on AWS (ec2), I wanted to change my kernel from AWS to a generic one. When I try it the suggested way with changing the Grub Config, it stops the machine. This is because Jibri (...
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Why does grub's os-prober add entries with `linux` instead of `linuxefi`

On my system, I have two copies of CentOS 7 installed, and one copy of Windows 10 Pro. Every system is bootable and works correctly, and is fully up to date (kernels, packages, the works). When I run ...
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Properly Configuring Grub for a Two-drive raid1 to Support Boot After a Drive Failure

Edit: So, I think the question still applies below, but I realized that the system is actually booting on the second drive, it's just missing /home, /boot and /etc/fstab. I am sure there is more ...
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Cannot boot from initramfs (unable to switch root, sysroot directory is empty)

Okay, so I have a problem with Fedora 34. More specifically, I have a problem with a custom built image that is part of the services that we deliver. The Problem The problem has to do with initramfs. ...
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ESXi installation PXE boot with GRUB on BIOS (not EFI)

all documents mention syslinux/pxelinux as a way to pxeboot ESXi installation, but I'd like to stay with GRUB 2. How to do that? I'm able, of course, to load GRUB 2 via network (i386-pc/core.0 for non-...
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How to avoid password change when boot GRUB in debian 10 system?

Per this post,I know it's easy to change password when boot GRUB. When I read set debian grub password ,I run command as below: cat << EOF >> /boot/grub/menu.lst timeout 3 password hackme ...
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Urgent help needed with GRUB centos

Today I had an email of OVH saying my server was hacked (it was nothing more than a wordpress plugin of a client messing around) but it ended with my server forced to Rescue Mode and I'm not able to ...
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grub rescue on Ubuntu 18.04 with btrfs partition

I have a small server (HP ProLiant MicroServer Gen8) running Ubuntu 18.04 64 bit with the latest HWE generic kernel (5.4.0.74.83~18.04.67); it has two SATA drives, GPT partitioned but booting in ...
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Reshape root disk from raid1 to raid5 on live system

I have server with CentOS 7 and grub2. It is in hosting company so I can not reinstall it. Server root / is installed on (mdadm) RAID1. Size is 4 TB, but is made somehow without EFI. These is small /...
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Apache2 stopped working after upgrade to v2.4 ((38)Function not implemented: AH00141)

I was happily running apache2 and mysql on a Ubuntu 16.04 server with no problems, but yesterday I noticed that there were a bunch of updates available and I installed them using apt-get. One of the ...
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Virtualbox not recognizing GRUB

I ripped a Linux Mint partition into a file using the dd command: sudo dd if=PART_PATH of=OUTPUT_PATH/ubuntu.bin Then I converted it into a *.vdi VBoxManage convertdd PATH_TO_ubuntu.bin ubuntu.vdi --...
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Grub2-install: warning: Couldn't find physical volume in Centos 7

After replacing the disk with raid 1, I have this problem: grub2-install --recheck /dev/nvme0n1 Installing for i386-pc platform. grub2-install: warning: Couldn't find physical volume `(null)'. Some ...
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Create GRUB Entry for Booting into CentOS Installation Media

Normally when installing CentOS 7, you download the ISO, write it to a thumb drive and boot it. However, I have a unique scenario where I'd like to be able to place the CentOS 7 installation files on ...
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How to move /boot and / to different disk

I have Debian server with multiple HDDs. /, /home/, swap and others are LVM Logical Volumes. /boot is on a small partition at the beginning of one of the physical HDDs. fstab uses UUID for /boot and /...
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GRUB2 theme looks broken after update (2.02->2.04)

Coming from Grub 2.02, and upgrading to 2.04, adding it to our TFTP server for PXE booting; I built the new grub2 image as in: /tmp/rebuild_grub/bin/grub2-mkimage -c ./grub-embedded.cfg -p '(tftp)/...
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Detect different keys on GRUB2 menu

I have a GRUB configuration that looks like the following, where I would like to detect different key inputs so I can act accordingly, but this does not work by default: echo "" echo -n &...
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Move root partition from one disk to another in Debian 10

I have installed Debian 10 on a hard disk in a partition in a logical volume(name: deb10). Now I want to move the running installation to a logical volume on a SSD(name: deb10ssd). I copied the files ...
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Auto boot degraded RAID1 on Debian 10 (Buster)

I want my server to boot without manual intervention on degraded RAID1 from second drive on Debian 10 (Buster). It boots when I detach the second hard disk but it doesn't boot when I detach the first ...
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Wrong grub2 prefix when booting over network

I have dnsmasq in proxy mode, serving pxe service and tftp server using this config: port=0 log-dhcp log-queries log-facility=/var/log/dnsmasq.log dhcp-range=192.168.0.0,proxy enable-tftp tftp-root=/...
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CentOS 7: small smiley face on boot?

I've got a problem with a CentOS 7 dedicated server. I've had it for years, and never had any problems with it until now. I did a yum update the other day, and then rebooted the machine, and it ...
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How to get rid of GRUB2 error "failure reading sector 0xb30 from `fd0'" on HP server

When I boot into my HP ProLiant DL120 G7 server's GRUB2 rescue shell, I get the following output: error: failure reading sector 0xb30 from `fd0'. error: failure reading sector 0x0 from `fd0'. error: ...
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unattended memtest: is it practical?

I will be building a medium scale cluster (20 nodes, expanding later) and for various reasons, using commodity hardware should give me a significant cost saving (even allowing for shorter operational ...
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No boot in Devuan after installation - EFI Shell

I installed Devuan ASCII on a virtual machine on VirtualBox. Installation went smooth, but after installation I get the following EFI shell See the image But any attempt to enter a BLK* device ended ...
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Booting a squashed filesystem from ISO

I am trying to create a UEFI bootable CD ISO with a squashed filesystem from a virtual machine, which I provisioned with the stuff I need. To explain: I use packer and a kickstart file to install ...
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In CentOS 7, is there a way to specify which block devices should be tuned with the scheduler (or ELEVATOR)?

In CentOS 6, there was /etc/tune-profiles/my-server/ktune.sysconfig with this text(I'm referring to the comments that explain what the code is doing): # This is the I/O scheduler ktune will use. ...
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Centos 7 no input in grub serial console

I use serial over lan console on intel S1200V3RPL server board. It worked nicely, but filesystem got corrupted and I had to reinstall. I've setup serial console the same way,but there is no input in ...
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Chainloading syslinux using grub2

I created a syslinux/isolinux hybrid CD iso to boot either legacy bios or eufi depending on what is needed. The legacy bios part works well and has worked for many years. I am using the newest (6.0.3) ...
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Are my EFI partitions mutually bootable? How to interpret the output of efibootmgr -v

I have two GPT formatted disks both starting with EFI partitions and followed by a single physical raid partition. I installed ubuntu-server 16.04 with software raid over these two raid partitions and ...
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Ubuntu 18.04 server failed grub install

I am trying a fresh install of Ubuntu 18.04 server, without an internet connection (not Live) on my Dell PowerEdge R640. The machine came with a Boot Optimized Storage SSD (RAID 1), which is where I'm ...
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Centos server gets stuck on grub prompt

I have a server on OVH with Cpanel which has 2 x 2TB partitions and its lsblk command output looks like this. http://prntscr.com/nz4xd2 A few days back I ran some upgrades and after rebooting my ...
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Grub incorrectly escapes $ character in its settings

Not sure where I make mistake but I can't escape $ correctly in /etc/default/grub. I'm on Ubuntu MATE 18.04. This is what I do: In console I edit confid by calling sudo mcedit /etc/default/grub I ...
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Auto-assemble RAID1 Array with mdadm on CentOS 7.6

I'm new to this particular area of the Stack Exchange network so please be kind. We are experiencing issues with auto-assembling a RAID1 Array created with mdadm on CentOS 7.6, and no matter what we ...
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CentOS7 not booting after "yum update" mokListRT fails

I updated CentOS 7 via yum update Didn't know about shim and mokutils so didn't exclude that from yum. Now I can't boot it, I can recover the files on it using another live distro (e.g. ubuntu), but ...
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Grub stuck at menu until I connect to console using VNC

I installed an Ubuntu 16.04 Server virtual machine on FreeNAS. Everything works as expected, except GRUB. When I reboot the machine with sudo reboot, it does not boot automatically. Every time I have ...
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Editing /boot/grub/grub.conf not recommended - yet how do you then change entries?

For example, our /boot/grub/grub.conf looks like this: ## ## End Default Options ## title Debian GNU/Linux, kernel 3.2.0-4-amd64 root (hd0,0) kernel /boot/vmlinuz-3.2.0-...
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How to fix "Setting up grub-pc" freezing during apt-get upgrade?

I have a packer script that builds up a virtual image using Ubuntu. The script today started getting stuck during apt-get dist-upgrade on amazon-ebs: Setting up grub-pc. I found many people on the ...
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What are the steps to convert an EBS boot volume from MBR to GPT without data loss? (Using Ubuntu)

I would like to extend one of my Ubuntu servers main/boot drive beyond 2TB. I know that I need to convert the drive to use GPT, and I'm confident that I can extend the size as needed once I'm able to ...
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GRUB2 Not Loading from MBR

I have a new computer that I have imaged using PXE. It loads a kernel, initrd and verifies if it needs to apply an image. If it does, it goes through some logic of partitioning (BIOS, non-GPT) the ...
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I deleted all the contents of /boot and now server is not booting

I did something stupid. My thinking was that /boot directory is empty and contents come to /boot each time the computer starts. My /boot drive was giving me error messages no space left so I thought ...
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grub2-mkconfig not working

I've updated the /etc/grub.d/40_custom for a custom menu entry as follows: menuentry "My OS"{ rootnoverify (hd1,0) chainloader +1 } I run this command: grub2-mkconfig –o /boot/grub2/grub.cfg ...
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Debugging boot loop after Ubuntu 18.04

I recently did a kernel update on a s2600cp server running Ubuntu 18.04. When booting into the latest installed kernel version from GRUB. My monitor displays a blinking cursor in the top left corner, ...
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linux/grub2: capturing boot errors for later analysis?

I'm running grub2 under my 4.15.0-30-generic x86_64 linux system. Every time I boot and select this system's entry in the grub menu (or any other system's entry), a screen or two of logged bootup ...
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