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3. LILO configuration dialog

Now that you know a little more of what LILO can do, let's see how you can configure it using Linuxconf. The main configuration dialog is split into sections. Here is an introduction to each section.

3.1 Global features

This section deals with how to install LILO.

Disabling LILO

If you boot your Linux system without LILO, you may find Linuxconf a little annoying as it tries to make sure LILO is properly set up. You can disable LILO support from Linuxconf at any time. However, this only affects Linuxconf. This does nothing else. It won't UN-install LILO. It just says ``stop checking LILO'' to Linuxconf.

Install boot sector on

LILO is brought to life at boot time by running a tiny program, called the boot sector. This program must be installed in a strategic location. The pop-up list of this field offers you a list of choices in order of preference. If Linux is the active partition, it does not matter much. If it is not, or your Linux partition is not on the first hard drive, you must install the boot sector either on the master boot record of the first drive, or on a boot floppy.

Note that installing the boot sector on a boot floppy is still quite fast, because it only needs to read one sector. All other files still live in the Linux partition on your hard drive.

If you have another boot manager (i.e. OS/2 boot manager, or Partition Magic), then a safe choice is to install the boot sector in the Linux partition. However, you will have to tell your other boot manager about this new partition. The OS/2 boot manager can boot (as LILO does) Linux, even if it is located on a second hard drive (not the primary one).

BIOS boot mode

Known to boot faster. Known not to work on some machines.

Boot table encoding

LILO creates a table which lets the boot loader locate the kernel files. This encoding is either done as track/head/sector or as a linear block number. With some SCSI controllers, the first strategy does not work. If you experience this, try to use the linear mode. Most modern computers work fine when you use a linear block number.

Present the LILO prompt

With this option, LILO will show its prompt. This option is on by default.

        LILO boot:

From there you can

At the prompt, you may select a configuration by pressing the <TAB> key to get a list of configurations. Type the label of a configuration or simply hit the <ENTER> key to select the default configuration.

If you need to pass boot-time parameters to the kernel, you will need to type the name of the configuration first, even if it is the default configuration.

Prompt timeout

Without a timeout, LILO will wait forever at the prompt. You can specify a timeout, after which, LILO will automatically boot the default configuration. The default timeout is 5 seconds.

Boot delay

LILO may boot immediately or it may wait some time before presenting the LILO boot prompt, provided it is so configured. Alternatively, LILO may display the prompt while booting if it is configured to show it. During this wait, you can intercept the boot sequence by hitting Shift-Tab. LILO will then present you with its normal boot: prompt.

If you disable the prompt, a boot delay of 5 seconds is recommended. Entering 0 disables this delay.

Message file

You must put the path to a text file. Ideally, the text will be short and fill the screen, leaving the LILO prompt at the bottom. This is used for the boot floppies of some distributions. You can use it, for example, to give boot instructions to users in a lab or to family members who might not remember which keys to press.

3.2 Defaults

This section provides the default configuration, which Linuxconf applies to different Linux configuration entries. Entering information here allows you to avoid entering it repeatedly later.

Root partition

You must set where your Linux root partition is located. A pop-up list gives you a list of all partitions.

RAM disk size

RAM disks are used for installation boot disks. They are seldom used for full configurations. The recent development of kernel modules has made RAM disk runtime configurable. A value of 0 disables the RAM disk feature.

Boot mode: read only?

Normally, this flag is on. For UMSDOS installation, it is off. UMSDOS installation will generally use loadlin to boot instead of LILO anyway.

Unless you really know what you're doing, leave it on. This is why: when Linux boots in read-only mode, it is allowed to do extensive inspections of the partitions without modifying them. This is especially valuable, if the boot follows a crash that has left the partitions in a weird state.

Why all the fuss about not touching the partition? Well, Linux supports multiple time stamps per file. One is the ``last access date.'' This means that the filesystem has changed (data has been written to the disk) because the files have been read (which is exactly what happens at boot time).

This "last access date" stamp is quite useful, but it becomes a nuisance at boot time. The "read only" setting tells Linux to drop this behavior.

After the partition has been checked, the system will be set back to "read write" mode automatically.

Boot options

Some drivers require information to correctly initialize themselves. For example, some CD-ROM drives do not correctly identify themselves. In order to tell Linux to consider your "rather broken" CD-ROM drive as a CD-ROM drive, you might need something like this:


This will tell Linux that the master IDE device on the second IDE interface (that is, /dev/hdc) is a CD-ROM device.

3.3 Linux setups

The default section is followed by several identical sections. Each sections defines one Linux boot configuration. Each boot configuration repeats all the parameters of the default section. You can simply override them in each section if you wish to change them.

The first configuration will be the default. This means that LILO will boot this one unless told differently at the boot: prompt.

Only three fields differ from the default section.

Delete this configuration

If you check this box, the configuration will disappear when you hit the accept button.

Kernel image file

This is the path to the kernel file, which boots with this configuration. Note that one kernel file may be used within several configurations.


This is a short name uniquely identifying the configuration. Given that a kernel file may be shared by several configurations, we need a unique key. This will be used when intercepting the boot process. LILO only expects a label name and will boot the corresponding configuration.

3.4 Other operating systems

LILO is able to boot almost any OS. For each OS you want to boot, simply specify the partition and a label. Then LILO simply loads the boot sector of that partition and launches it.

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