Grub.conf File Explanation

#vim /boot/grub/grub.conf

# grub.conf generated by anaconda

#

# Note that you do not have to rerun grub after making changes to this file

# NOTICE:  You have a /boot partition.  This means that

#          all kernel and initrd paths are relative to /boot/, eg.

#          root (hd0,2)

#          kernel /vmlinuz-version ro root=/dev/sda5

#          initrd /initrd-version.img

#boot=/dev/sda

default=0

timeout=5

splashimage=(hd0,2)/grub/splash.xpm.gz

hiddenmenu

title Red Hat Enterprise Linux Server (2.6.18-8.el5)

      root (hd0,2)

      kernel /vmlinuz-2.6.18-8.el5 ro root=LABEL=/ rhgb quiet

      initrd /initrd-2.6.18-8.el5.img

root (hd0,2) :- in this line root means root file system is loaded in hd0. hd0 is a HDD name u have more HDDs if  you have another os also in that specify the hdd name and change the default booting os. 2 means second hard drive.

Default=0 :- means if you have multiple OS you can change the boot priority here.

Timeout=5 :- means if you not press any button within 5 seconds it will boot the default OS. If you want increase or decrease the time here.

Hiddenmenu :- means if you want display the how many OS i have  in hdd on booting time without pressing any key just put the ‘#’ before hiddenmenu.

Ex:- #hiddenmenu 

Tittle Red hat Enterprises Linux :- it will display the name of the server. On booting time if you want specify the name to this server change the name.

Kernel means the kernel 2.6.18.8.el5 is loaded under /boot/vmlinuz

In this 2.6.18.-8.el5 means :- if you have 2 other then intel we can install the operating syste. 6=even number (stable) if you have odd number (bita one) if you a stable operating system you will get the support from red hat people. 18=patches or added in to this. 8=bugs rectifications el5=enterprises version 5.