Booting and Shutdown in HP-UX Release 11i Version 1.5

Booting From an Alternate Kernel

Chapter 14

Booting From an Alternate Kernel

By default, the boot process will use the main kernel ﬁle /stand/vmunix

to ﬁnd the kernel to boot from. To boot from a different kernel, you must

interact with the initial program loader (IPL/ISL) and specify a different

main kernel ﬁle:

Step 1. Follow the procedure for booting from an alternate device (given below)

to the point where you can interact with the initial program loader (IPL /

ISL).

Step 2. As part of the device-ﬁle argument in the hpux boot command, specify

the HP-UX path name of the main kernel ﬁle of the alternate kernel that

you want to boot. For example:

ISL> hpux boot disk(2/4.0.0;0)/stand/

alt_kernel_file_name

NOTE Although the kernel is no longer composed of the single main kernel ﬁle

(by default /stand/vmunix); the main kernel ﬁle carries the name of the

kernel and contains internal kernel identiﬁcation that isused by the boot

loader to obtain information about all of the kernel components that

need to be loaded during the boot process.

If you have performed whole kernel conﬁguration following the steps

outlined in the white paper Reconﬁguring the Kernel in HP-UX Release

11i Version 1.5, the newly conﬁgured kernel should have been properly

updated using kmupdate (1M). By running kmupdate, not only does the

newly conﬁgured kernel become bootable, but it becomes the default

kernel accessible from /stand/vmunix. Therefore, you do not need to

specify an alternate main kernel ﬁle path name to boot a newly

conﬁgured kernel.

You may want to boot from a different kernel when /stand/vmunix fails

to boot, and you want to boot from the previous kernel saved by the

kmupdate command (/stand/vmunix.prev). You may also want to boot

from a kernel with a different name that you have saved using the

recommended procedures in the section “Saving a Backup Kernel

Permanently” in the white paper Reconﬁguring the Kernel in HP-UX

Release 11i Version 1.5.