eXTReMe Tracker
Dec 062011

The newer releases of Ubuntu and Linux Mint have started getting stuck during LiveCD installation or after distribution/kernel upgrade.  Usually the point where it gets stagnant is when it reaches this line:


Nothing happens past that point. A solution or a workaround to this is to insert the nolapic acpi=off switch in the grub boot line. There are 3 ways to do this:

1: If you are starting a fresh install from a CD and the installation pauses at the kernel_thread_helper line, you need to restart your computer.

When you boot from your installation CD, choose F6 before you continue trying out the LiveCD. This give you boot option at the bottom of your screen.

At the very end of the line add nolapic acpi=off and hit enter to continue booting from LiveCD. In most cases this should work.

2. The same problem may arise when you do a distribution upgrade or even a kernel upgrade. In that case you need to change your grub.cfg file. Follow these steps:

sudo nano /boot/grub/grub.cfg

Enter your sudo password and it will bring you to your grub menu configuration.

Look for the section that read similar to this:

menuentry 'Ubuntu, with Linux 2.6.38-11-generic' --class ubuntu --class gnu-linux --class gnu --class os {
 set gfxpayload=$linux_gfx_mode
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos6)'
 search --no-floppy --fs-uuid --set=root 337e2841-fc82-61b3-84be-5a9c71ae43b8
  linux   /boot/vmlinuz-2.6.38-11-generic root=UUID=337e2841-fc82-61b3-84be-5a9c71ae43b8 ro quiet splash vt.handoff=7
 initrd  /boot/initrd.img-2.6.38-11-generic

You want to change the line that I have identified above to read:

linux   /boot/vmlinuz-2.6.38-11-generic root=UUID=337e2841-fc82-61b3-84be-5a9c71ae43b8 ro quiet splash vt.handoff=7 nolapic acpi=off

After adding these switches to the boot menu option, press ctrl-X, then save and exit.

This is for a permanent change if you can boot using an older kernel.

3: If you cannot login to an older kernel or recovery mode because of the kernel_thread_helper error,  you have to press “e” (without the quotation marks)  to edit the boot options when you get the grub menu.

For the kernel you want to use, edit the end of the line that reads

linux   /boot/vmlinuz-2.6.38-11-generic root=UUID=337e2841-fc82-61b3-84be-5a9c71ae43b8 ro quiet splash vt.handoff=7


linux   /boot/vmlinuz-2.6.38-11-generic root=UUID=337e2841-fc82-61b3-84be-5a9c71ae43b8 ro quiet splash vt.handoff=7 nolapic acpi=off

Press Enter and you should be able to boot.

  One Response to “Booting halts with kernel_thread_helper”

  1. I don’t know how good the HP recovery disks are at this, but you will need to repiar your MBR and Track 0 (Boot Track).This is a problem with GRUB and MCE or any version of Windows XP which has active antivirus. GRUB installs itself into the Hard Drive Boot Track, which looks like a corrupt Boot Record to MCE and XP. Virus scanners also detect GRUB as a virus and disable it entirely. Make an Image Backup of your Hard Drive with Paragon Backup (not Acronis True Image) or Norton Ghost before proceeding beyond this point! Include the MBR and Track 0 in your backup. Install Norton PartitionMagic 8 into your Windows Partition (normal program install). One way to avoid the Boot Track conflict problem is to create a small FAT-32 partition and install Norton BootMagic (comes with PartitionMagic, which can create all the needed partitions). BootMagic and its cousin, VCom System Commander, do not install into the Boot Track, and therefore rarely conflict with Windows XP in any flavor. So where does GRUB install? If you have already created a Linux Swap and a Linux ext-3 Partition (use PartitionMagic for this), when installing GRUB, stop and select where GRUB should install. You will need to uncover the non-default options, and know that Linux orders the partitions by numbers, not by letters as Windows does. Your Linux ext-3 partition will probably be the largest Linux formatted partition on your drive, and that is where you tell GRUB to install. Then install Ubuntu into the same partition as GRUB.BootMagic can then be told to add the Linux partition to its boot menu, and the next time you boot, both Windows XP and Ubuntu (Linux) will be available from the BootMagic Splash Screen when the computer begins to boot. This avoids the MBR and Track 0 conflicts which can make Windows and/or Linux unbootable after just one or two boot ups.

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