How does grub2-Mkconfig work?
The grub2-mkconfig command creates a new configuration based on the currently running system. It collects information from the /boot partition (or directory), from the /etc/default/grub file, and the customizable scripts in /etc/grub.
What is Mkconfig?
It is used to tell GRUB 2 where the generated GRUB configuration file should be saved. By default, grub2-mkconfig or the grub-mkconfig command prints the generated configuration file to STDOUT, which is the terminal of your Linux operating system.
What is the difference between GRUB and grub2?
GRUB and GRUB2 are two different versions. GRUB2 is considered as default boot loader of Ubuntu whereas GRUB is generally used in RHEL older versions. When started, GRUB2 mainly presents a menu and waits for some input from users. It generally transfers control to our operating system kernel.
How do I manually load kernel in GRUB?
Booting From grub> The second line tells GRUB the location of the kernel you want to use. Start typing /boot/vmli , and then use tab-completion to fill in the rest. Type root=/dev/sdX to set the location of the root filesystem. Yes, this seems redundant, but if you leave this out you’ll get a kernel panic.
How do you regenerate grubs?
Rebuild the grub.cfg file by running the grub2-mkconfig -o command as follows:
- On BIOS-based machines, issue the following command as root : ~]# grub2-mkconfig -o /boot/grub2/grub.cfg.
- On UEFI-based machines, issue the following command as root : ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg.
Where are grub2 configuration files stored?
/boot/grub folder
The main Grub 2 configuration file, normally located in the /boot/grub folder, is grub. cfg. It is the product of various scripts and should not normally be edited directly.
How does GRUB2 work in Linux?
GRUB2 provides the same boot functionality as GRUB1 but GRUB2 is also a mainframe-like command-based pre-OS environment and allows more flexibility during the pre-boot phase. GRUB2 is configured with /boot/grub2/grub. cfg. The primary function of either GRUB is to get the Linux kernel loaded into memory and running.
What is GRUB2 EFI?
GRUB 2 (GRand Unified Bootloader version 2), sometimes stylized as GRUB2 and commonly referred to as GRUB, is a multiboot secondary bootloader capable of loading kernels from a variety of filesystems on most system architectures. GRUB supports PC BIOS, PC EFI, IEEE 1275 (Open Firmware), SPARC, and MIPS Lemote Yeeloong.
How do I manually load a kernel?
At the Grub prompt, enter the boot command. If you’ve provided the proper information, then the kernel should take over control and you should see familiar processes scroll and your server boot. When complete, if you need to re-install Grub or repair your disks, you will need to do so at that time.
How do I load a kernel?
Linux config file to load a kernel module You need to edit the file named /etc/modules or put a new config file in /etc/modules-load. d/ directory. Use any one of the methods for loading kernel modules. The configuration file consists of a set of lines.
How do I edit grub config?
To edit grub, make your changes to /etc/default/grub . Then run sudo update-grub . The update-grub will make the permanent changes to your grub. cfg file.
How do I create a grub2 config file?
Use the grub2-mkconfig command to generate grub. cfg. This command uses the template scripts in /etc/grub. d and menu-configuration settings taken from /etc/default/grub when generating grub.