Reconfiguring the Kernel in HP-UX Release 11i Version 1.5

Reconfiguring the kernel in HP-UX Release 11i Version 1.5
Reconfiguring the Kernel
Chapter 110
Saving a Backup Kernel Permanently
System administrators and kernel developers often like to save a trusted good kernel (for
example, the default kernel, /stand/vmunix, running at the end of a clean OS installation),
before starting the process of building new kernels.
Although the kmupdate (1M) command always saves the previous /stand/vmunix kernel to
the kernel name /stand/vmunix.prev, you must be aware that a subsequent use of
kmupdate will again overwrite the vmunix.prev kernel. The recommended way to
permanently save /stand/vmunix is to move (do not copy)/stand/vmunix to a safe name
such as /stand/vmunix.bkup.
Furthermore, if /stand/vmunix had been the running kernel, we recommend an immediate
reboot from the renamed location:
# mv /stand/vmunix /stand/vmunix.bkup
# shutdown -r
Once /stand/vmunix has been moved, there is no longer a default kernel from which to boot,
until a new kernel is configured and updated with the kmupdate command. To boot from a
non-default kernel, refer to “Booting from an Alternate Kernel” in the chapter “Administering
a System: Booting and Shutdown,” in Managing Systems and Workgroups: A Guidefor HP-UX
System Administrators.
CAUTION Although the main kernel file (for example /stand/vmunix) carries the name of
the kernel, you must remember that a kernel is no longer contained in that
single file, but is composed of several essential files, and depends on a specific
directory structure and symbolic links to be set properly for the kernel to be
able to boot. The old unsupported practice of copying the /stand/vmunix file
may result in the eventual loss of the kernel component set necessary to boot
the copy.