Changing kernel parameters in HP-UX

Changing kernel parameters in HP-UX.


While Installing DB it failed due to  below kernel parameters


Checking for maxssiz=134217728; maxssiz=8388608.         Failed <<<<
Checking for maxssiz_64bit=1073741824; maxssiz_64bit=268435456.         Failed <<<<
Checking for maxuprc=3687; maxuprc=3686.         Failed <<<<
Checking for semmns=8192; semmns=4096.          Failed <<<<


I resolved this issue by setting this parameters using kctune command as below.


For verifying the current Value

# kctune -v for  maxssiz maxssiz_64bit maxuprc semmns
Tunable             maxssiz
Description         Maximum size of the stack segment of a 32-bit process (bytes)
Module              vm
Current Value       8388608 [Default]
Value at Next Boot  8388608 [Default]
Value at Last Boot  8388608
Default Value       8388608
Constraints         maxssiz >= 262144
                    maxssiz <= 401604608
Can Change          Immediately or at Next Boot


Tunable             maxssiz_64bit
Description         Maximum size of the stack segment of a 64-bit process (bytes)
Module              vm
Current Value       268435456 [Default]
Value at Next Boot  268435456 [Default]
Value at Last Boot  268435456
Default Value       268435456
Constraints         maxssiz_64bit >= 262144
                    maxssiz_64bit <= 2147483648
Can Change          Immediately or at Next Boot


Tunable             maxuprc
Description         Maximum number of processes for each non-root user
Module              pm_proc
Current Value       3686 [((nproc*9)/10)]
Value at Next Boot  3687
Value at Last Boot  3686
Default Value       256
Constraints         maxuprc >= 3
                    maxuprc <= nproc - 5
Can Change          Immediately or at Next Boot


Tunable             semmns
Description         Maximum number of semaphores
Module              pm_usync
Current Value       4096 [Default]
Value at Next Boot  4096 
Value at Last Boot  4096
Default Value       4096
Constraints         semmns >= 2
                    semmns <= 335534080
                    semmns >= semmni
                    semmns >= semume
Can Change          At Next Boot Only


For changing the Value:


# kctune maxssiz=134217728
     ==> Update the automatic 'backup' configuration first? yes
             yes     - Update backup before every change
             once    - Update backup now; ask for each future change
             no      - Don't update backup now; ask for each future change
             disable - Don't update backup before any change
     ==> Update the automatic 'backup' configuration first? yes
       * The automatic 'backup' configuration has been updated.
       * Future operations will update the backup without prompting.
       * The requested changes have been applied to the currently
         running configuration.
Tunable                Value  Expression  Changes
maxssiz  (before)    8388608  Default     Immed
         (now)     134217728  134217728


# kctune maxssiz_64bit=1073741824
       * The automatic 'backup' configuration has been updated.
       * The requested changes have been applied to the currently
         running configuration.
Tunable                       Value  Expression  Changes
maxssiz_64bit  (before)   268435456  Default     Immed
               (now)     1073741824  1073741824


# kctune maxuprc=3687
       * The automatic 'backup' configuration has been updated.
       * The requested changes have been applied to the currently
         running configuration.
Tunable            Value  Expression      Changes
maxuprc  (before)   3686  ((nproc*9)/10)  Immed
         (now)      3687  3687


# kctune semmns=8192
NOTE:    The requested changes could not be applied to the currently
         running system, for the following reasons:
         - The tunable 'semmns' cannot be changed without a reboot.
       * The requested changes have been saved, and will take effect at
         next boot.
NOTE:    No change to the tunable 'semmns' was needed.
Tunable               Value  Expression
semmns   (now)         4096  Default
         (next boot)   8192  8192


After Changing the value using kctune command, it require a reboot of the system for some of the value to get effected. As show below output.


 
# kctune -v for  maxssiz maxssiz_64bit maxuprc semmns
Tunable             maxssiz
Description         Maximum size of the stack segment of a 32-bit process (bytes)
Module              vm
Current Value       134217728
Value at Next Boot  134217728
Value at Last Boot  134217728
Default Value       8388608
Constraints         maxssiz >= 262144
                    maxssiz <= 401604608
Can Change          Immediately or at Next Boot


Tunable             maxssiz_64bit
Description         Maximum size of the stack segment of a 64-bit process (bytes)
Module              vm
Current Value       1073741824
Value at Next Boot  1073741824
Value at Last Boot  1073741824
Default Value       268435456
Constraints         maxssiz_64bit >= 262144
                    maxssiz_64bit <= 2147483648
Can Change          Immediately or at Next Boot


Tunable             maxuprc
Description         Maximum number of processes for each non-root user
Module              pm_proc
Current Value       3687
Value at Next Boot  3687
Value at Last Boot  3687
Default Value       256
Constraints         maxuprc >= 3
                    maxuprc <= nproc - 5
Can Change          Immediately or at Next Boot


Tunable             semmns
Description         Maximum number of semaphores
Module              pm_usync
Current Value       8192
Value at Next Boot  8192
Value at Last Boot  8192
Default Value       4096
Constraints         semmns >= 2
                    semmns <= 335534080
                    semmns >= semmni
                    semmns >= semume
Can Change          At Next Boot Only