How do I set the default GRUB kernel?
Table of Contents
Inspect the GRUB2 menu during boot or open /boot/grub/grub. cfg for inspection. Determine the location of the desired kernel on the main menu or submenu. Edit the “GRUB_DEFAULT” setting in /etc/default/grub and save the file.
How do I change the default GRUB boot in CentOS 7?
How to change the default kernel in GRUB for RHEL and CentOS
- Step 1: Get installed kernel versions.
- Step 2: Use grub2-set-default command.
- Step 3: Check grubenv file.
- Step 4: Rebuild Grub.cfg file.
- Step 5: Restart Server.
How do I find my grub kernel version?
2 Answers
- Look at the /proc/version file. cat /proc/version.
- Look at the contents of the dmesg command. dmesg | grep Linux.
- Look in the kernel/source code directories. ls /boot.
How do I find the default kernel in RHEL 7?
You can also refer to it by the /etc/grub2. cfg file which is a symbolic link. To force a system to always use a particular menu entry and to set default boot kernel, use the menu entry name as the key to the GRUB_DEFAULT directive in the /etc/default/grub file.
How do I open GRUB boot menu?
With BIOS, quickly press and hold the Shift key, which will bring up the GNU GRUB menu. (If you see the Ubuntu logo, you’ve missed the point where you can enter the GRUB menu.) With UEFI press (perhaps several times) the Escape key to get grub menu. Select the line which starts with “Advanced options”.
How do I change the default kernel in Oracle 7?
Change Default Kernel in Oracle Linux 7 The value saved allows you to use the grub2-set-default and grub2-reboot commands to specify the default entry. grub2-set-default sets the default entry for all subsequent reboots and grub2-reboot sets the default entry for the next reboot only.
How do I change kernel?
To switch kernels on Arch, can be simply done by installing the kernel that you want to use and tweak the grub configuration file.
- Step 1: Install the kernel of your choice.
- Step 2: Tweak the grub configuration file to add more kernel options.
- Step 3: Re-generate the GRUB configuration file.
How do I list all kernels?
The easiest and quickest way to check all installed Kernels in a Linux is by using find command. As you see in the above output, there are two Linux Kernels versions (5.4. 0-64 and 5.4. 0-65) are installed in my Ubuntu desktop machine.
Where is kernel located in Linux?
/boot folder
Where Are the Linux Kernel Files? The kernel file, in Ubuntu, is stored in your /boot folder and is called vmlinuz-version.
How to change default kernel in Grub for RHEL and CentOS?
How to change the default kernel in GRUB for RHEL and CentOS 1 Step 1: Get installed kernel versions. 2 Step 2: Use grub2-set-default command. 3 Step 3: Check grubenv file. 4 Step 4: Rebuild Grub.cfg file. 5 Step 5: Restart Server. I’m a IT Infrastructure and Operations Architect with extensive experience and administration… More
What does default=0 mean in Grub?
The directive “ default=0 ” means that GRUB boots the first kernel entry by default, unless you override this action. 2. Change the value of “default” to the value of the desired kernel to boot by default, that correspond to any of the installed kernels.
How do I change the default Grub entry value in Linux?
For example, the kernel 2.6.32-431 is assigned GRUB entry value 1 in the above screenshot. Open /boot/grub/grub.conf with a text editor, look for default=N, and change N to the GRUB entry value for the default kernel to use.
How to change the default boot kernel on CentOS 6?
The first step to change the default boot kernel on CentOS 6 is to get a list of all available kernel images added to GRUB. The following command will show you the list. From the list, identify the kernel that you want to set as default. Each kernel in the list is assigned by GRUB a numeric entry value starting from 0 in an increasing order.