8.6. Configuring the Boot Loader with YaST

This YaST module simplifies the configuration of the boot loader. However, you should not experiment with this module unless you understand the concepts behind it. The following discussion mainly covers the default boot loader GRUB.

[Important]Important

Do not change the boot method of a running system unless you really know what you are doing.

In the YaST Control Center, select System+Boot Loader Configuration. The current boot loader configuration of your system will be displayed, enabling you to make any needed changes (see Figure 8.1. “Configuring the Boot Loader with YaST”).

Figure 8.1. Configuring the Boot Loader with YaST

Configuring the Boot Loader with YaST

8.6.1. The Main Window

The table listing the configuration data consists of three columns. Under Changed (to the left), flags mark the changed options listed in the center column. To add an option, click Add. To change the value of an existing option, select it with a mouse click and click Edit. If you do not want to use an existing option at all, select it and click Delete.

Reset offers the following options:

Propose New Configuration

Generates a new configuration suggestion. Older Linux versions or other operating systems found on other partitions will be included in the boot menu, enabling you to boot Linux or its old boot loader. The latter takes you to a second boot menu.

Start from Scratch

Enables you to create the entire configuration from scratch. No suggestions are generated.

Reread Configuration from Disk

If you already performed some changes and are not satisfied with the result, reload your current configuration with this option.

Propose and Merge with Existing GRUB Menus

If another operating system and an older Linux version are installed in other partitions, the menu is generated from an entry for the new SUSE LINUX, an entry for the other system, and all entries of the old boot loader menu. This procedure might take some time. This is not possible if LILO is used.

Restore MBR of Hard Disk

The backup MBR saved on the hard disk is written back.

Use Edit Configuration Files to edit the relevant configuration files in an editor. To edit a file, load it by means of the selection field. Click OK to save your changes. To exit the boot loader configuration, click Cancel. Click Back to return to the main window.

[Warning]Warning

Remember that the sequence of the options or commands is very important in GRUB. If the specified sequence is not followed, the machine may not boot.

8.6.2. Boot Loader Configuration Options

For less experienced users, configuration with YaST is easier than editing the files directly. Select an option and click Edit to open a dialog in which to change the settings according to your needs. Click OK to confirm the changes and return to the main menu, where you can edit other options. The available options depend on the boot loader used. The following list introduces some options of the boot loader GRUB:

Boot Loader Type

Use this option to switch between GRUB and LILO. Continue to another dialog in which to specify the way in which this change should be performed. For instance, convert the current GRUB configuration into a similar LILO configuration. However, some settings may be lost if no equivalent options are available. You can also create a new configuration from scratch or generate and edit a suggestion for a configuration.

If you start the boot loader configuration in the running system, you can load the configuration from the hard disk. If you decide to return to the original boot loader, you can load its configuration by means of the last option. However, this possibility only exists as long as you do not close the boot loader module.

Boot Loader Location

Use this dialog to define where to install the boot loader: in the master boot record (MBR), in the boot sector of the boot partition (if available), in the the boot sector of the root partition, or on a floppy disk. Use Others to specify a different location.

Disk Order

If your computer has more than one hard disk, specify the boot sequence of the disks as defined in the BIOS setup of the machine.

Default Section

With this option you set the kernel or operating system that should be booted by default. The selected system is booted after the time-out. In this menu you get a list of all boot menu entries with the button Edit. Select an entry from the list and click Set as Default. At this point, you may also modify any entry by using the Edit button.

Available Sections

The existing entries of the boot menu are listed under this option in the main window. If you select this option then click Edit, a dialog opens that is identical to the Default Entry dialog.

Make Boot Loader Partition Active

Use this option to activate the partition whose boot sector holds the boot loader, independently from the partition on which the directory with the helper files of the boot loader are stored (/boot or the root directory /).

Replace Code in MBR

Specify whether to overwrite the MBR, which may be necessary if you have changed the location of the boot loader.

Back up Files and Parts of Hard Disks

Backs up the changed hard disk areas.

Add Saved MBR to Boot Loader Menu

Adds the saved MBR to the boot loader menu.

Use Time-out to define how many seconds the boot loader should wait for keyboard input before the default system is booted. A number of other options can be specified with Add. However, the use of these options requires a deeper understanding and is not covered here. Refer to the manual pages of GRUB and LILO (man grub, man lilo, and man lilo.conf). Additionally, a detailed online manual for GRUB is available at http://www.gnu.org/software/grub/.