Explain About Grub.conf file in Redhat Linux Server

Grub.conf file it has 7 lines. there default file format.
title Red Hat Enterprise Linux Server (2.6.18-53.el5)
root (hd0,0)
kernel /vmlinuz-2.6.18-53.el5 ro root=/dev/VolGroup00/LogVol00
initrd /initrd-2.6.18-53.el5.img

FIRST LINE: timeout=5
while the system boot it will wait up to 5 second user to select the kernel.

SECOND LINE: splashimage=(hd0,0)/grub/splash.xpm.
it will load the (hd0,0)/grub/splash.xpm.  image as the background when we were booting the OS
How to create teh splash.xpm.gz Image
#convert imagelocation.png -resize 640x480 -colors 14 splash.xpm
#gzip splash.xpm

THIRD LINE:title Red Hat Enterprise Linux Server (2.6.18-53.el5)
It will give the kernel label as the “title Red Hat Enterprise Linux Server (2.6.18-53.el5)”

FOURTH LINE:root (hd0,0)
Here (hdx,y) x -> Hard Drive y-> Partition
we need to give the Correct partition
otherwise it will through following error message
Error 22: No such partition

FIFTH LINE:kernel /vmlinuz-2.6.18-53.el5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
it will load the kernel image and mount root file system as mention in root=
/dev/VolGroup00/LogVol00 refer to the logical volume root file system located in these logical volume.

And kernal execute /sbin/init process it is parent process PID is 1.

SIX LINE:initrd /initrd-2.6.18-53.el5.img
initrd it has executable driver module.
initrd Intilize the Ram Disk
if we face the any problem to load initrd we need to reinstall by using mkinitrd.


ajay kumar singh said...

very nice, through this i realy cleared my concepts