System Management Guide: Operating System and Devices

Creating Boot Images

To install the base operating system or to access a system that will not boot from the system hard drive, you need a boot image. This procedure describes how to create boot images. The boot image varies for each type of device. The associated RAM disk file system contains device configuration routines for the following devices:

• Disk
• Tape
• CD-ROM
• Network Token-Ring, Ethernet, or FDDI device

Prerequisites

• You must have root user authority to use the bosboot command.
• The /tmp file system must have at least 20 MB of free space.
• The physical disk must contain the boot logical volume. To determine which disk device to specify, type the following at a command prompt:

  lsvg -l rootvg
  

  The lsvg -l command lists the logical volumes on the root volume group (rootvg). From this list you can find the name of the boot logical volume. Then type the following at a command prompt:

  lsvg -M rootvg
  

  The lsvg -M command lists the physical disks that contain the various logical volumes.

Creating a Boot Image on a Boot Logical Volume

If the base operating system is being installed (either a new installation or an update), the bosboot command is called to place the boot image on the boot logical volume. The boot logical volume is a physically contiguous area on the disk created through the Logical Volume Manager (LVM) during installation.

The bosboot command does the following:

1. Checks the file system to see if there is enough room to create the boot image.
2. Creates a RAM file system using the mkfs command and a prototype file.
3. Calls the mkboot command, which merges the kernel and the RAM file system into a boot image.
4. Writes the boot image to the boot logical volume.

To create a boot image on the default boot logical volume on the fixed disk, type the following at a command prompt:

bosboot -a

OR:

bosboot -ad /dev/ipldevice

Note: Do not reboot the machine if the bosboot command fails while creating a boot image. Resolve the problem and run the bosboot command to successful completion.

You must reboot the system for the new boot image to be available for use.

Creating a Boot Image for a Network Device

To create a boot image for an Ethernet boot, type the following at a command prompt:

bosboot -ad /dev/ent

For a Token-Ring boot:

bosboot -ad /dev/tok