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Meaning of kernel configurations in 11.23 and after
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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
This page was last modified on 13 October 2009, at 12:24. This page has been accessed 2,187 times.