This is the main different between the Legacy GRUB and GRUB 2.
In legacy GRUB, GRUB files is located under /boot/grub/, and there is a menu.lst file that is reading during boot and which contents is displayed to the user in the GRUB menu.
But in GRUB 2 it is distributed through three core locations. There is a file grub.cfg in privies location (/boot/grub/) which replaces the menu.lst file and this is the main configuration file. Beyond that another two files are there located in two different places.
- /etc/grub.d/GRUB scripts are contained here and those scripts create grub.cfg file when the relevant grub command is execute.
- /etc/grub.d/ Here is the place contains grub settings. Grub scripts are looking here before create the grub.cfg file when the relevant grub command is execute.
• Install/re-install GRUB
In Legacy GRUB we are opening GRUB shell by typing sudo grub as a super user. Then we can use it to install or reinstall to MBL (master boot loader) or a particular partition boot sector. But at GRUB 2 this is partially different. In this case the command is sudo grub-install. We can use this command at the BASH (SHELL) as a supper user to do the same process.
• Partition numbering has been changed
So, In GRUB 2, first hard driver and first partition instance is numbering as (hd0, 1).
• Replaces the geometry command.
In Legacy GRUB, there is command called geometry, is used for list down the devices as GRUB sees them on our PC. But in GRUB 2 introduce ls command for the same purpose.
• GRUB Legacy uses stages is replaced
In GRUB 2 uses boot.img and core.img files for instead stage 1 and stage 2 which are using legacy GRUB. Normally Legacy GRUB has three stages, stage 1, stage 1.5 and stage 2. Stage 1.5 has been neglected here or stage 1.5 and stage 2 both are replaced with stage 2 by core.img file.
And those are some of differences which are found out by me in this session. Finally I have to say GRUB 2 is more efficient, powerful in many ways than Legacy GRUB.