tunning the kernel

[Maicon Stihler]

Hi, I need to adjust the following kernel parammeters: SHMMAX SEMMNI SEMMNS MAX_THREAD_PROC NFLOCKS MAXDSIZ MAXSSIZ MAXTSIZ and ulimit(DATA) ulimit(STACK) ulimit(NOFILES)

I tried using kmtune but it refused to adjust some parammeters with this message:
WARNING: xxxx cannot be set dynamically

Im totally new to HP-UX and have no idea how to set it up. Do I need to build a new kernel? If so, where can I find some free docs on how to do it?

Thank you

[Stephen Keane · Accepted solution]

login as root and run sam
go to "Kernel configuration" then "Configurable parameters"

change the paremeters you want and then "Actions" -> "Process new kernel"

[lawrenzo]

Best and easiest way is using sam - you will find that some settings cannot be changed unless you follow the specified formula.

Server will need a reboot after the changes#

HTH

[Henk Geurts]

hi Maicon.
docs :
http://docs.hp.com/en/TKP-90202/index.html
(page12)

lots of docs to be found
at
http://docs.hp.com
search for kernel configuration.

regards,

[Maicon Stihler]

I did it with sam, now when I do a "kmtune -l" it reports something like this:

Parameter: maxssiz
Current: 8388608
Planned: 209715200
Default: 209715200
Minimum: -
Module: -
Version: -
Dynamic: No

Why does the "Current" is smaller than the "Planned" ? I rebooted the system after processing the new kernel.

[KCS_1]

Hi,

Some kernel parameters that you've changed are not dynamic paramerters as you listed "Dynamic : no" needs to reboot the system to take effect after reconfigured kernel parameters.

Do reboot the system for building new kernel.

[Maicon Stihler]

Strangely it reports the same after the reboot. Im doing this from a remote location. Does it need human intervention during the boot time to the new changes to take effect?

[KCS_1]

If you reconfigured the parameters(all you need) by SAM, after changed them, a message shows up for rebuilding a new kernel and taking effect system reboot is required.

In my case, normally follow the kernel parameter changing sequence in SAM
1. change to new value
2. create a new kernel ( rebuild )
3. reboot (take effect)



Regards,

[Maicon Stihler]

Uh, I dont really understand what is going wrong. I used sam to change the kernel parameters,when I finished I when to Action -> process a new kernel... then it worked for a while, at the end it asked me if I wanted to move the new kernel to its place, I said yes, it worked a bit more and then told me to reboot the machine. After the reboot I still get a "current" value smaller then the "planned" value.

I tried building the kernel manualy following a doc by HP. Using kmupdate at the end. Then I rebooted the system, and it remains the same.

Probably I am missing something on the process, but I dont have enough time to read through all the docs with a guy asking me all the time if the machine is ready.

[Maicon Stihler]

I attached the output of kmtune, shouldnt the values listed in "Planned" take effect after the reboot?

[Maicon Stihler]

Does I need to change on sam:
Choose One to Modify Parameter:
<*> Specify New Formula/Value
< > Use Formula in Source File

?

[侯力?]

Modify the kernel parameter: maxfiles (old = 60)

[Shameer.V.A]

Hi Maicon,
You are doing a big mistake.
You SHOULD NOT Use REBOOT command. You should use shutdown -r now. reboot will not move the new kernel for booting.

Please taken a backup of existing kernel before doing any kernel rebuild.

Please find the attached doc for reference..


Regards,

Shameer