Meaning of kernel configurations in 11.23 and after
There have been significant changes to kernel managment since the previous release (B.11.11 / B.11.22). The config, kmadmin, kminstall, kmmodreg, kmsystem, and kmupdate commands are obsolete and have been removed.
The kmtune, kmpath, and mk_kernel commands have been deprecated and are obsolescent. Only some of their options are supported in this release, and they will be removed altogether in future releases.
Here is a list of directories and their meanings that now exist with B.11.23 and later versions of HP-UX:
*Currently running kernel: /stand/current/
*Copy of the current config prior to changes: /stand/backup/
*Kernel config originally installed with OS /stand/last_install/
*Link to the config to be used at the next boot: /stand/nextboot/
*Automatically created after any crash dump: /stand/crashconfig/
*There are also two special files in /stand:
/stand/vmunix is a hard link to /stand/current/vmunix
/stand/system is a soft link to /stand/nextboot/system
Below you will find the steps needed to manually tune and revert to a previous kernel on B.11.23.
NOTE: You can find these steps documented in the following whitepaper document: [1] http://h71028.www7.hp.com/erc/downloads/5981-7111en.pdf
The first thing you should do is list the current config:
# kconfig -v
Configuration backup
Title Automatic Backup
Save Time Mon Dec 22 13:39:54 2003
Modify Time Mon Dec 22 13:39:54 2003
Kernel Path /stand/backup/vmunix
Configuration crashconfig
Title imported from /stand/system
Save Time Mon Dec 8 13:49:33 2003
Modify Time Mon Dec 15 13:37:52 2003
Kernel Path /stand/crashconfig/vmunix
Configuration last_install
Title Created by last OS install
Save Time Mon Dec 1 13:59:37 2003
Modify Time Mon Dec 1 13:59:38 2003
Kernel Path /stand/last_install/vmunix
- Save the current config
# kconfig -C "Saved config for March 5th 2004" -s march0504 * The current configuration has been saved to 'march0504'.
# kconfig -t march0504 "Mod of config on march 5th 2004" * The title of the configuration 'march0504' has been set to "Mod of config on march 5th 2004".
This has created a directory /stand/march0504 and copied the current kernel 'vmunix' into it. At this point you should repeat step 1. and you should see the saved configuration.
NOTE: A configuration can be deleted using:
# kconfig -d <config_name>
- Modify some kernel parameters with kctune or kcmodule.
# kctune -C "Changing buffer cache" dbc_max_pct=25
WARNING: The automatic 'backup' configuration currently contains the
configuration that was in use before the last reboot of this
system.
==> Do you wish to update it to contain the current configuration
before making the requested change? y
* The automatic 'backup' configuration has been updated.
* The requested changes have been applied to the currently running system.
Tunable Value Expression Changes
dbc_max_pct (before) 50 Default Immed <--- NOTE: Dynamic parameter
(now) 25 25
# kcmodule -C "Adding module stape" stape=best
NOTE: The configuration being loaded contains the following change(s)
that cannot be applied immediately and which will be held for
the next boot:
-- The configuration is supposed to include a module 'stape' which
is not available without a kernel rebuild.
* The automatic 'backup' configuration has been updated.
* Building a new kernel for configuration 'nextboot'...
* Adding version information to new kernel...
* The requested changes have been saved, and will take effect at
next boot.
Module State Cause
stape (now) unused
(next boot) static explicit
# shutdown -r -y 0
NOTE: To revert back to the previous 'march0504' kernel type:
# kconfig -C "Reverting back to config of March 5th 2004" -l march0504