Chapter 16. Reconfiguring the HP-UX Kernel | HP Certified: HP-UX System Administration

Chapter Syllabus

16.1 Why Reconfigure the Kernel?

16.2 The Reconfiguration Process

16.3 Kernel Rebuilding in a Nutshell

16.4 Booting from the Old Kernel

16.5 Common Kernel Tunable Parameters

16.6 Using SAM to Reconfigure the Kernel

The default HP-UX kernel is stored in the /stand directory with the name vmunix . Kernel configuration is a process of rebuilding the kernel after adding or removing drivers or subsystems. You also need to rebuild the kernel if you change kernel parameters, such as the maximum number of processes in memory. HP-UX is shipped with all supported device drivers and subsystems present in the /usr/conf directory. Support of new devices is provided through kernel patches. The kernel is also rebuilt after installing any kernel patches.

The kernel rebuilding process can be divided into three major steps. In the first step, the kernel configuration file /stand/system is created and/or modified to incorporate the required changes. In the second step, the kernel is regenerated. Then, in the third step, you install the newly generated kernel and reboot your system. If all goes well, the new kernel is loaded at reboot time. After that you can verify whether the required changes were made or you need to repeat the process.

In this chapter, first you will see in which circumstances you need to build a new kernel and what the kernel configuration process is. Then you will look at the kernel configuration file and how to change parameters in it. Sometimes you are not able to boot your system with the new kernel due to a problem in the regeneration process or a misconfigured kernel parameter. In that case, you need to boot your system from the old kernel. You will learn how to do so in the event that you are caught in such a situation. In the last part of the chapter, you will find information about some common kernel tunable parameters and how to use SAM for kernel configuration.

After reading the chapter, you will be able to reconfigure the HP-UX kernel to incorporate new subsystems, drivers, and system parameters. You will also learn commands to list existing drivers known to the kernel and the value of system parameters.

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