About tunable parameters
Tunable system parameters affect the settings of various system tables.
The default tunable parameter values
are acceptable for most configurations and applications.
If your application has special performance needs,
you might have to experiment with different combinations of
parameter values to find an optimal set.
There are two types of tunable parameters: kernel and internet (TCP/IP).
-
Kernel system tunable parameters reside
in the kernel configuration directories /etc/conf/mtune.d (see
Mtune(DSP))
and /etc/conf/autotune.d. (see
Autotune(DSP)
).
Kernel system tunable parameters all have upper-case names
(for example; DMA_PERCENT, MAXRSS).
The SCOadmin
Hardware/Kernel Manager (
configure(ADM))
or the
idtune(ADM)
command are used to examine and modify kernel tunable parameters.
You must use
idbuild(ADM)
to rebuild your system and reboot in order for changes to become effective.
-
Internet (TCP/IP) tunable parameters reside in
/etc/inet/inet.dfl.
All internet tunable parameters have lower-case names
(for example: udpprintfs, tcp_2msl, ipforwarding).
Internet tunable parameters should be modified using the
inconfig(ADMN)
command.
A reboot or rebuild is not required for changes to take effect,
but is generally recommended.
(If, for example, you turn off ipforwarding on a router
without rebooting, erratic behavior and error messages can result.)
CAUTION:
Though you can examine the Mtune, Autotune
and inet.dfl files to determine the tunable parameter
settings for your system, you should never modify these files directly.
Some parameters are autotuned and do not normally require manual tuning.
Next topic:
Autotuned parameters
Previous topic:
Configuring kernel parameters
© 2007 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 05 June 2007