HP-UX Reference (11i v3 07/02) - 1M System Administration Commands A-M (vol 3)

k
kctune(1M) kctune(1M)
NAME
kctune - manage kernel tunable parameters
SYNOPSIS
kctune [-dghuvDS][-b behavior][
-c config][-C comment][-F fmt]
[
-m module][-P fields][arg]...
DESCRIPTION
kctune is the administrative command for HP-UX kernel tunable parameters. It gives information about
tunable parameters and their values, and makes changes to tunable values.
This command can work with any saved kernel configuration, or with the currently running kernel
configuration, depending on the use of the
-c flag (see below). By default, changes to the currently run-
ning kernel configuration are applied immediately. Some changes cannot be applied without a reboot; if
any such changes are requested, or the
-h
flag is given, all changes on the kctune command line will be
held until next boot.
Only users with appropriate privileges can make changes to tunable values.
Options
-b behavior Specifies whether or not to update the automatic backup configuration before the
requested change. Also specifies the default backup behavior for future changes. See
kconfig(5) for a description of the various backup behaviors. Not valid in combination with
-c.
For compatibility with old 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.
-c config kctune will view or change tunables in the saved kernel configuration named config.If
this option is not specified,
kctune will view or change tunables in the currently running
kernel configuration.
See kconfig(5) for more information on saved kernel configurations.
-C comment The specified comment will be included in the kernel configuration log file entry made for
this invocation of kctune. For more details on the kernel configuration log file, see
kclog(1M). Note that it will usually be necessary to quote the comment in order to avoid
interpretation by the shell.
-d Adds the description of each tunable to the output.
-D Restricts output to only those parameters which have changes being held until next boot.
kctune will return 1 if there are any such parameters; see RETURN VALUE below. Not
valid in combination with
-c.
-F fmt Formats all tunable values according to the specified format, which must be one of the char-
acters d, u, o,orx, representing signed decimal, unsigned decimal, octal, or hexadecimal,
respectively. In the absence of this option, kctune chooses an appropriate format for
each tunable.
-g Group related tunables. The tunables in the output will be grouped and sorted by the ker-
nel modules that define them. Note: the set of tunables defined by each kernel module may
change in future releases of HP-UX.
-h Changes will be held until next boot, even if they could be applied immediately. Not valid
in combination with -c.
-m module Tells kctune to include in its output only those tunables which are defined by the
specified module.
-P fields Tells kctune to include only the specified fields in its output, and to print them in the
machine-readable form described in kconfig(5). See the Developers Note, below. Not valid
in combination with -d, -g,or-v.
-S Only tunables with non-default values will be included in the output. Not valid in combina-
tion with -D.
-u Allow the creation of user-defined tunables. Normally, kctune will not accept any tunable
name that does not identify an existing tunable. When the -u option is given, kctune
will accept an assignment to an unrecognized tunable name and use it to define a new
HP-UX 11i Version 3: February 2007 − 1 − Hewlett-Packard Company 395