What is meant by automatic tuned kernel parameter in hp-ux

[Md. Minhaz Khan]

Dear Experts,

Please give a details understanding about automatic tuned kernel parameter. Below is my understanding:

I am taking "nfile" for the example. Default value of "nfile" in HP-UX 11.23 is 65536. As this parameter has " Automatic Tuning Enabled" feature, when number of open files of exceed in the system >65536 then system will automatically adjust the value ???

Thanks
Minhaz

[Ismail Azad]

Hi Minhaz,

An automatic tuned kernel parameter is a parameter that is automatically tuned by the kernel as default behaviour (of automatic) unless you override the parameter with another value otherwise the kernel will auto tune the parameter according to the requirements. However, this does not happen for a static, dynamic and a user defined parameter and there values are dependent on what you define and are not automatically tuned by the kernel itself. Nfiles is deprecated in 11.31 and is denoted as a private kernel parameter. If it helps, do assign points.

Regards

Regards
Ismail

[Md. Minhaz Khan]

Dear Ismail brother,

So For HP-UX 11.23,if number of open files exceed in the system ">65536" then Kernel will automatically adjust the value ??

Please see below command output:

# kctune -v nfile
Tunable nfile
Description Maximum number of file descriptors (system-wide)
Module fs
Current Value 65536 [Default]
Value at Next Boot Default (automatic)
Value at Last Boot 65536
Default Value 65536 (automatic)
Constraints nfile >= 2048
nfile <= 2147483647
nfile >= (2 * maxles_lim)

Can Change Automatic Tuning Enabled

[Ismail Azad]

Minhaz,

Your output shows automatic and since it is set as default the kernel should automatically tune nfiles. However, if you override the default behaviour then the kernel will not automatically tune. This is the definition of a tunable type "automatic"

Regards