How do I change my grub UUID?

How do I change my grub UUID?

Procedure

1. Ubuntu 14.04: Run blkid to obtain the UUID of the root partition. Modify the /boot/grub/grub.
2. CentOS 6.5: Run blkid to obtain the UUID of the root partition. Modify the /boot/grub/grub.
3. CentOS 7.0: Run blkid to obtain the UUID of the root partition. Modify the /boot/grub2/grub.

How do I customize the grub menu?

You can customize the Grub bootloader by simply editing the /etc/default/grub. cfg file. Grub allows users to tweak even the slightest of details in the boot menu. For beginners, Linux might be a bit hard to adapt to.

How do I add options to grub?

Using GRUB

1. Press e when GRUB appears. A new screen appears with more options.
2. Modify the boot options as needed. To add a boot option, navigate with the arrows of the keyboard to the end of the line that starts with linux. Type the boot option that you want to add.
3. Press Ctrl+X, F10, or Fn+F10 to start Tails.

How do I change my UUID?

1. Changing UUID using tune2fs

1. To be able to change the UUID of the filesystem, it must be umounted first. # umount /data.
2. The tune2fs command allows the UUID to be changed using the -U flag.
3. When modifying existing UUIDs, make sure to update any references to the old labels in fstab.
4. Mount the filesystem back again.

How do I change the default grub entry?

Change grub boot order

1. sudo nano /etc/default/grub. Find the following line.
2. GRUB_DEFAULT=0. Edit the line replacing 0 by the item number you want to boot by default.
3. GRUB_DEFAULT=2.
4. sudo update-grub.
5. GRUB_TIMEOUT=10.
6. GRUB_CMDLINE_LINUX_DEFAULT=”splash”
7. GRUB_CMDLINE_LINUX_DEFAULT=”text”
8. sudo update-grub.

How do I set kernel options?

Reboot your system and hold the Shift key as its first booting up, and you will be brough into the GRUB boot menu. Highlight the kernel you want to edit (probably the first selection in the menu) and press e on your keyboard to temporarily edit the boot parameters.

What does a UUID tell you?

UUIDs are generally used for identifying information that needs to be unique within a system or network thereof. Their uniqueness and low probability in being repeated makes them useful for being associative keys in databases and identifiers for physical hardware within an organization.

How do I encode a UUID?

The steps we will take to transform or encode the UUID are:

1. Define our encoding alphabet.
2. Remove grouping hyphens.
3. Convert UUID to binary representation.
4. Convert binary into integers (base 10).
5. Use integers to reference characters from our encoding alphabet.
6. Return encoded string.

How does Grub read the root variable in embedded configuration files?

After the embedded configuration file (if any) is executed, GRUB will load the ‘ normal ’ module (see normal ), which will then read the real configuration file from $prefix/grub.cfg. By this point, the root variable will also have been set to the root device name.

What is HD0 in Grub?

I do notice that in grub, if I drop to a grub command prompt and do an ls, the only hard disk I see listed is hd0 when my system actually has 4 hard disks. As I mentioned above, hd0 is the hard disk that has grub and my Linux installs.

Is there a way to get the device hint in Grub?

This is not described in the GRUB Manual but there is documentation to be found in GRUB itself ( search –help on the GRUB shell): –hint First try the device HINT.

How do I embed a configuration file in a grub image?

To embed a configuration file, use the -c option to grub-mkimage. The file is copied into the core image, so it may reside anywhere on the file system, and may be removed after running grub-mkimage .