Secugenius Hacking Tutorials: GRUB GRUB INSTALL AND GRUB PROBLEMS WITH GRUB FILE

GRUB /GRUB INSTALL/ AND GRUB PROBLEMS WITH GRUB FILE

GRUB:- GRUB IS THE BOOTLOADER FOR THE LINUX. AND IF THERE IS ANY PROBLEM IN

THE GRUB FILE THE SYSTEM WILL NOT LOGIN EVEN NOT BOOT.

PROBLEM 1_______ IF WHOLE GRUB BOOTLOADER`S CONFIGURATION FILES ARE DELETED

WE HAVE TO INSTALL THE GRUB

Boot pc from the RHEL5 DVD THEN PRESS ANY KEY

LINUX RESCUE _________enter to enter in the linux rescue mode

After reaching at the shell mode

Sh-3.1# grub-install /dev/sda ____________ at last is the hdd address

This is the command to install the grub boot loader

Check for login

Sh-3.1# login

Passwd *******

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

GRUB.CONF FILE____________________

1…

The grub file has its most important configuration that is as FOR SINGLE OPERATING SYSTEM

Default=0__________________it is the priority no of o/s to boot first by default {0} for Linux if put{1} then xp boot.

Timeout=5 _________________seconds for the wait to system boot on which o/s

Title REDHAT Enterprises Linux -2.6.18-53.el5 __________ title for the o/s

Root (hd0,0) __________________________________address of partition on which boot loader install.

Kernel /vmlinuz-2.6.18-53.el5 ro root=/dev/sda2 ___ kernel and the partition address on which kernel install.

Initrd /initrd-2.6.18-53.el5.img________________address of the ram , data stored in it in compressed form.

THIS IS THE MOST IMPORTANT FILE TO REMEMBER FOR RHCE…………………………………………..

2…

The grub file has its most important configuration that is as FOR DUAL BOOT OPERATING SYSTEM

Default=0__________________it is the priority no of o/s to boot first by default {0} for Linux if put{1} then xp boot.

Timeout=5 _________________seconds for the wait to system boot on which o/s

Title REDHAT Enterprises Linux -2.6.18-53.el5 __________ title for the o/s

Root (hd0,3) __________________________________address of partition on which boot loader install.

Kernel /vmlinuz-2.6.18-53.el5 ro root=/dev/sda5 ___ kernel and the partition address on which kernel install.

Initrd /initrd-2.6.18-53.el5.img________________address of the ram , data stored in it in compressed form.

Title other

Rootnoverify (hd0,0)________________-because we first install the other o/s so it gets the first addres.

Chainloader+1

Because we install the other o/s before the LINUX it takes the hdd address after the partitions of the first installed O/S

BUT THE BOOT LOADER OF THE LINUX IS INSTALLED IN THE LAST PARTITION OF THE OTHER O/S SO IF YOU DELETE THE LAST PARTITION OF THE OTHER O/S THE BOOT LOASDER GRUB IS AUTOMATICALLY DELETED THEN YOU HAVE TO

REINSTALL THE GRUB BY { grub-install /dev/sda} comnd

1__ PROBLEM __ IF GRUB.CONF IS DELETED FROM

/BOOT/GRUB/GRUB.CONF

THEN BOOT THE SYSTEM IT WILL STOP ON THE GRUB

Grub > find /grub/stage1 ___________ to find the address of partition with which /boot and / are related

Or in which the boot loader configuration is stored .