Grub Config file
 

Hi everyone,

Actually I am learning about the grub config.
I restarted my system and pressed ESC and got the grub menu which is having 3 lines as

root (rh0,0)
Kernel /....
initrd /intramfs......

like this.....my question is
If I make changes to the 1st line it is not allowing to boot the system and if I make any changes in the next 2 lines...it is booting and changes are not saved also.....why this is happening????

you should find the information on grub file on google very easily. I would suggest you go through the docs first. Changing a grub file without understanding it is not a good idea

The first line sets the root partition, if you change that the system will not find the root partition and will not boot.
The second line sets the kernel image.
The third line starts booting into linux.
And as adviced by chaitanya that first you should get good understanding about grub then you should go for experimenting on it.

And to add to that, the changes that you make on grub prompt are temporary in nature that affect only the current boot. Those will not be saved. To make the changes permanent, you need to edit grub configuration file. You only edit grub parameters for debugging or troubleshooting purposes like lost root password or kernel panic due to mismatched or wrong root partition.