[Chinese-English control] Booting Process in Linux RHEL 7 | Linux RHEL 7 Boot process

Booting Process in Linux RHEL 7 | Linux RHEL 7 Boot process

In this post, I'll guide you booting process in Linux RHEL 7, it's very important to know the Linux booting process to Troubleshoot and fix boot issues. Redhat 7 replaced the init process (/sbin/init) with Systemd (/USR/LIB/SYSTEMD/SYSTEMD), SYSTEMD provides considerably mor E control compared to the INIT process does, although still supporting existing init scripts.
In this article, I'll walk you through the boot process for Linux RHEL 7. Understanding the Linux startup process is important for troubleshooting and fixing startup problems. RedHat 7 replaces the init process (/sbin/init) with Systemd (/USR/LIB/SYSTEMD/SYSTEMD). SYSTEMD provides more boot control than the traditional init process, although it still supports existing init scripts.

Linux boot Process Step by step:
Linux Start-up process

1. BIOS (Perform POST) | BIOS (perform power on self test)
2. MBR (loads GRUB2) | Load GRUB2
3. GRUB2

• Loads the Vmlinuz kernel image load vmlinuz kernel image
• Extract the contents of Initramfs image extract content from Initramfs image

4. KERNEL

• Loads necessary driver modules from INITRD image loads the necessary driver modules from the INITRD image
• SYSTEMD starts systems First process SYSTEMD start a system

5. SYSTEMD

• Reads conf files from/etc/systemd reading configuration files from/etc/systemd
• Reads file linked By/etc/systemd/system/default.target reads the files that the/etc/systemd/system/default.target points to
• Brings the system to the state defined is booted to the status defined by the systems target

RHEL 7 Booting process:
RHEL 7 startup process

Bios:
BIOS full Form are Basic input/output System, it is a software which helps in booting process when the power was on, it exec Utes the Power On Self Test (POST) to identify, test and initialize system hardware components and its loads the MBR.
The BIOS represents the basic input-output system, which is a software that helps to boot, and when powered on, it performs post to identify, test, and initialize the system hardware components, loading the master boot record (MBR).

Master Boot Record (MBR)
It is the information in the first sector (bytes) of any Linux booting disk drive, which identifies where and how an ope Rating system is situated. Out of bytes Boot-loader contains in 446 bytes, Next, bytes contains the partition table for the disk. Last 2 bytes are called Magic number, which is used for error detection. MBR detects the bootable device and loads the GRUB2 boot loader into memory and transfers control over to it.
Xxxx

GRUB2 Bootloader:
GRUB stands for GRand Unified Boot-loader. In Redhat 7, Grub 2 are the default boot loader program, Grub boot loader were used in previous RHEL versions. Configuration file for GRUB2 is located at/boot/grub2/grub.cfg. GRUB2 do a search for Vmlinuz kernel image file in The/boot and loads the Vmlinuz kernel image file into memory and extra CT the items in the Initramfs image file into TMPFS (temporary file system).
Xxxx

Initramfs:it would pre-load the block devices modules, for EXAMPLE:SCSI, IDE, so, and the root file system, on which thos E modules normally reside, can then be accessed and mounted.
Xxxx

KERNEL:
The Initramfs is bound to the kernel and the kernel mounts this Initramfs as part of a two-stage boot process.
Kernel starts the SYSTEMD process with a process ID of 1 (PID 1).
Xxxx

SYSTEMD:
SYSTEMD is a init system used in boot process in Linux RHEL 7 to bootstrap the user space and manage all processes Subseq uently. Systemd brings the machine to the State based on the system target, performing system initialization tasks such as:
Xxxx

• Initializing the Network
• Setting the Host-name
• Initializing Se-linux
• Initializing the system hardware based on kernel boot arguments
• Mounting the file systems, including virtual file systems such as The/proc file system
• Starting swapping

I Hope this article provides your the information about, booting Process in Linux RHEL 7. Thank for studying!!. Be social and share it in social media,if you really feel worth sharing it.
Xxxx

Extended Reading

• A Basic Guide to Linux Boot Process
• 6 Stages of Linux Boot Process (Startup Sequence)
• How Linux Boots, Run levels, and Service Control
• Quick HOWTO:Ch07:The Linux Boot Process
• Inside the Linux boot process
• Wikipedia:linux startup process
• Systemd Boot Process A Close look in Linux

[Chinese-English control] Booting Process in Linux RHEL 7 | Linux RHEL 7 Boot process