GRUB 2 is the default boot loader and manager for Ubuntu 9.10 (Karmic Koala) and many other operating systems. As the computer starts GRUB 2 either presents a menu and awaits user input or automatically transfers control to an operating system kernel. GRUB 2 is a descendant of GRUB (Grand Unified Boot loader). It has been completely rewritten to provide the user significantly increased flexibility and performance. GRUB 2 is Open Source software.
To determine your version, use grub-install -v. (grub1.96 or later)
GRUB2’s ADVANTAGES OVER GRUB
- Scripting support including conditional statements and functions
- Dynamic module loading
- Rescue mode
- Custom Menus
- Graphical boot menu support and improved splash capability
- Boot LiveCD ISO images directly from hard drive
- New configuration file structure
- Non-x86 platform support (such as PowerPC)
- Universal support for UUIDs (not just Ubuntu)
GRUB vs GRUB2
GRUB 2’s default menu will look familiar to GRUB users but there are a great number of differences beneath the surface.
- On a new install of Ubuntu 9.10 with no other installed operating system, GRUB 2 will boot directly to the login prompt or Desktop. No menu will be displayed.
- Hold down SHIFT to display the menu during boot (formerly ESC in GRUB legacy).
- No /boot/grub/menu.lst. It has been replaced by /boot/grub/grub.cfg.
- There is no “/find boot/grub/stage1” at the grub prompt. Stage 1.5 has been eliminated.
- The main menu file, /boot/grub/grub.cfg, is not meant to be edited, even by ‘root’.
- grub.cfg is overwritten anytime there is a update, a kernel is added/removed, or the user runs update-grub
- The user can use a custom file, /etc/grub.d/40_custom, in which the user can place his own entries. This file will not be overwritten.
- The primary configuration file for changing menu display settings is /etc/default/grub.
- There are multiple files for configuring the menu – /etc/default/grub mentioned above, and all the files in the /etc/grub.d/ folder.
- Partition numbering has changed. The first partition is now 1 rather than 0. The first device is still 0, however (no change).
- Automated searches for other operating systems, such as Windows, whenever update-grub is executed.
- No changes made in the configuration files will take effect until the update-grub command is also run.
INSTALLATION OF GRUB2
GRUB 2 is installed by default on new installations of Ubuntu 9.10 (Karmic Koala). Releases such as Ubuntu 9.04 Jaunty Jackalope which are upgraded to 9.10 will retain GRUB unless the user elects to upgrade to GRUB 2. Previous releases of Ubuntu can be upgraded to GRUB 2 if the user desires.
You can check the current version installed on your system via Synaptic or from the command line. Open a Terminal (Applications > Accessories > Terminal) and enter the following: