Red Hat Linux5 Startup Process and troubleshooting

RedHat Linux 5 Startup Process and troubleshooting

Linux troubleshooting Technology

Linux Startup Process

Describes the Linux Startup Process and the configuration files and scripts used for Linux Startup.

Notes on Linux Startup Process

How many mini systems does the Linux Startup Process know?

Linux Startup Process

1 power-on ----- cmos --- (post power-on self-check program ------ mbr boot ---- grub menu

Boot self-check, MBR guide, GRUB menu, kernel loading, init process running, read/etc/inittab configuration file, and execute/etc/rc. d/rc. sysinit script/run/etc/rc. d/rc Script run/etc/rc. d/rc. local is to start the mingetty process, that is, the page on which we need to log on to the interface.

Let's take a look at the/etc/grub. conf file.

Figure 1

There is an example of an exam: If you automatically lose power 5 seconds after the boot,

It may be a sentence in/etc/rc. d/rc. local.

Sleep 5; shutdown-h now we just need to remove this sentence.

If an mbr boot error occurs

For example, we use these commands to simulate an MBR error and overwrite it

Dd if =/dev/zero of =/dev/sda bs = 446 count = 1

Restart init 6

The system cannot boot, that is, the first stage mbr error.

Figure 2

If we need to re-build the mbr, We need to restart it. We can also boot it with a CD. In the first step, we will first mount the CD and then restart it,

 

Then the page appears.

Figure 3

At this time, we need to enter the first aid mode of the system,

Boot: linuxe rescue and press ENTER

We will be prompted about the language we need to use. We can select English. The default value is enough.

Figure 4

Next, we will be prompted about the input method.

Figure 5

Then, we will be prompted whether to enable network NO.

Figure 6

The next rescue will explain to us. If we find your system, it will mount it to/mnt/sysimage and we will choose to continue

Figure 7

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