HP-UX Reference (11i v2 04/09) - 1M System Administration Commands A-M (vol 3)

k
kctune(1M) kctune(1M)
NAME
kctune - manage kernel tunable parameters
SYNOPSIS
kctune [-dghuvBDKS][-c config][
-C comment][-P fields][args]...
args are:
tunable (query tunable)
tunable
= (set tunable to default)
tunable=Default (set tunable to default)
tunable=expr (set tunable to expression)
tunable+=value (increase tunable by value)
tunable>=value (set tunable to value if currently less)
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.
Super-user permissions are required when making changes to tunable values.
Options
-B Forces a backup of the currently running configuration before making the requested
change. For more information on backup configurations, see kconfig(5). Not valid in
combination with -c.
-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 run-
ning 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.
-g Group related tunables. The tunables in the output will be grouped and sorted by the
kernel 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.
-K Prevents a backup of the currently running configuration before making the requested
change. For more information on backup configurations, see kconfig(5). Not valid in
combination with
-c.
-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 combi-
nation with -D.
-u Allow the creation of user-defined tunables. Normally, kctune will not accept any tun-
able 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
HP-UX 11i Version 2: September 2004 − 1 − Hewlett-Packard Company Section 1M−−353