HP-UX Reference (11i v3 07/02) - 5 Miscellaneous Topics (vol 9)

k
kconfig(5) kconfig(5)
NAME
kconfig - introduction to kernel configuration commands
DESCRIPTION
HP-UX contains a set of commands used to view and modify the configuration of the HP-UX kernel. The
commands are:
kconfig Operations on complete kernel configurations
kcmodule Operations on kernel modules
kctune Operations on kernel tunable parameters ("tunables")
kcpath Retrieves pathnames of kernel files
kclog Searches and displays the kernel configuration log file
mk_kernel Builds a kernel configuration from a system file
KERNEL CONFIGURATIONS
The set of data that controls the behavior and content of the HP-UX kernel is called a kernel configuration.
System administrators may save any number of kernel configurations, and may load any one of them at
any time. A kernel configuration consists of module usage choices made using kcmodule and tunable
values chosen using
kctune.
By default, these commands affect the state of the currently running system. When these commands are
given a -c config option, they instead affect the saved kernel configuration named config.
The currently running kernel configuration can be saved using
kconfig -s. A saved configuration can
be loaded using kconfig -l. This causes the state of the running system to be changed to match the
saved configuration. A saved configuration can be marked for use when the system is next booted, by using
kconfig -n. This makes no change to the state of the running system, but causes the specified saved
configuration to be loaded when the system is rebooted. (See Boot Behavior below.)
Saved kernel configuration names must start with a letter; contain only letters, digits, and underscores (_);
and be at most 32 characters in length. The names are case-distinct.
Backup Configuration
The system maintains a saved configuration called
backup, which can be used to recover from
configuration errors. Depending on the selected backup behavior, the system can automatically save the
currently running configuration to backup immediately before making any requested change to the
configuration. The backup behavior is set using the -b behavior option to the kconfig
, kcmodule ,or
kctune commands. The recognized backup behaviors are:
yes Always update the backup configuration before making a change.
once Update the backup configuration before making the current change. For sub-
sequent changes, ask whether to update it.
no Do not update the backup configuration before making the current change.
For subsequent changes, ask whether to update it.
disable Never update backup configuration before changes.
These behaviors can be abbreviated to one letter. For compatibility with previous releases, -B is
accepted as an alias for
-b yes, and -K is accepted as an alias for -b no. These aliases will be
removed in a future release.
After each boot, the default backup behavior is to ask whether to update the backup configuration before
each change. Changes made noninteractively assume a "no" response.
Dynamic and Static Changes
By default, the kernel configuration tools will apply configuration changes to the currently running system,
causing an immediate change in their behavior. System administrators can override this default by specify-
ing the -h option to changes made using the kconfig, kcmodule,orkctune commands. This option
causes the change(s) to be held until the system is rebooted. HP recommends that this option be used only
when the next reboot is expected to happen soon. If the reboot doesn’t happen for months after the change,
the change could come as an unwelcome surprise to an administrator who had forgotten the request.
214 Hewlett-Packard Company − 1 − HP-UX 11i Version 3: February 2007