HP-UX HB v13.00 Ch-07 - Kernel Configuration

HP-UX Handbook – Rev 13.00 Page 33 (of 33)
Chapter 07 Kernel Configuration
October 29, 2013
system is running, in response to changing system resources and needs. When a tunable is set to
default, its expression is reported as Default, as seen in the examples above. In these cases, the
system is free to choose the value it thinks optimal, and to change it as needed. HP recommends
that tunables be left set to default unless the default is known to be unsatisfactory.
NOTE: Setting a tunable to Default is not the same thing as setting it explicitly to the default
value reported by kctune. Using the example above, if you set nproc to 4200, its value will
remain 4200 until you change it. However, if you set nproc to Default, its value will be kept up
to date with any changes HP makes to the default value for nproc.
Some tunables have constraints on their values, which are shown in the verbose output.
Sometimes these are minimum and/or maximum values, as shown for nproc above. Other times
these are fixed relationships between tunables (for example, acctresume must be greater than
acctsuspend) or restrictions on the allowed values (for example, dnlc_hash_locks must be a
power of two). These constraints are enforced whenever tunable values are changed. There are
other constraints, not shown by kctune, that are based on the current state of the system and can
change over time (for example, nproc cannot be set to less than the number of processes
currently running). These constraints are enforced only when changing the currently running
system, and not when making changes held for use at next boot or changes to a saved
configuration.
Some tunables have restrictions on when their values can be changed. These restrictions are
noted in the kctune output. Tunables whose values can be changed immediately are marked
Immed. Tunables whose values can be automatically tuned by the system are marked Auto.
Tunables without either marking can only be changed with a reboot.
All HP-UX tunables have manpages. To obtain information about the behavior, allowed values,
and side effects of a tunable, consult the manpage for that tunable, which can be found in Section
5 of the online document.
Additional information
Reconfiguring the Kernel in HP-UX 11iv1
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01918628/c01918628.pdf
HP-UX System Administrator's Guide: Configuration Management
HP-UX 11i Version 3
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02281490/c02281490.pdf
Kernel parameters for HP-UX systems running Oracle E-Business Suite software
applications
http://h20195.www2.hp.com/v2/GetPDF.aspx/4AA1-6355ENW.pdf