Having issues with your Linux Ubuntu PC? Does your Linux Ubuntu computer freezes when rebooting/restart it? If yes, then how you stop it from freezing during reboot process.

It can be very annoying when you suddenly discovered that your Ubuntu pc hangs whenever you want to reboot it. Of course, there are many solutions and fixes you can easily find on the internet. However, some of these solutions might be too hard, confusing and technical.

Almost all Operating System usually have this problem. I’ve once experienced this issue on my Dell Latitude Windows 10. I can’t hibernate my pc because my pc is missing some hibernate files and I had to press the power button to on it again.

What Causes Linux Ubuntu to Freeze During Restart?

Well, there are many reasons that can make your Ubuntu PC freeze during the reboot process. The reasons for Linux Ubuntu freeze during restarts sometimes could be because of low RAM, but in most cases, your Linux (kernel) doesn’t know how to perform restart set by the BIOS you have on the machine.

Luckily, there are some few methods Linux kernel has that can be used to perform restarts/reboot process which you can choose from in order to fix your Ubuntu PC.

If you are experiencing this problem and you would like to fix it. Here’s how to fix it.

How to fix it

To fix this annoying problem, you’ll have to pass reboot parameter to the kernel at the boot time. So to do this in Ubuntu, you can easily navigate to and edit /etc/default/grub file. Then search for the following line:


Then from there, we can you can use the option command line options that will be passed to the kernel during boot. So enter the following command:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash reboot=pci"

The reboot=pci can also be used to solve the restart boot problem for most DELL laptops.

After entering the command line, you’ll need to enter the next command:

sudo update-grub

Then you’ll need to reboot machine your machine in order to make provided options to take effect. So enter the command below:

$ cat /proc/cmdline

BOOT_IMAGE=/boot/vmlinuz-3.11.0-12-generic root=UUID=b5fd9a8a-4675-4277-9843-56a5c44fefb4 ro quiet splash reboot=pci

After entering the above command, your Linux should reboot. Once your Linux have successfully rebooted with correct a reboot option, then your Linux reboot is working.

If it doesn’t work, you can also try other reboot options and they are as follows:

warm - don’t set the cold reboot flag

cold - set the cold reboot flag

bios - reboot by jumping through the BIOS (only for X86_32)

smp (reboot by executing reset on BSP or other CPU - only for X86_32)

triple - force a triple fault - init

kbd - use the keyboard controller. cold reset (default)

acpi - use the RESET_REG in the FADT

efi - use efi reset_system runtime service

pci - use the so-called “PCI reset register”, CF9

force - avoid anything that could hang

Majority of reboot process freezing cases are usually fixed with the bios, acpi or pci options.

Alternatively, you can easily pass multiple parameters at the same time in the reboot options and let Linux kernel to try them in order they are specified. With this, it tries all the available and checks which one will work for it. So in case you don’t know the one that will work for your ubuntu, you can just check if any of the parameters given will fix the issue. Enter the below command:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash reboot=warm,cold,bios,smp,triple,kbd,acpi,efi,pci,force"

That’s all. Your ubuntu won’t freeze again while rebooting once you’ve followed the steps and chosen the right reboot options that will work for you.

By admin

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