how to know the kernel features are enabled or disabled

[Ming Zhao]

Hi,

I am working on a RHEL3.0 without source code installed. Application team asked me to check if some kernel features are enabled:
COFNIG_NET
CONFIG_SYSVIPC
CONFIG_BINFMT_ELF
etc..

How to know if they are enabled or disabled.

Thanks,

[Stuart Browne]

Short of viewing the compiled-in '.config', (see /boot/config-2.4.xxxxx) some of them can be sorta difficult to figure out.

Short answers for the 3 listed:

If you have networking (at all), then CONFIG_NET is configured in.

If you can run most executables, CONFIG_BINFMT_ELF is configured in.

CONFIG_SYSVIPC will be compiled in, as it provides compatability with previous versions of SYS V IPC (Inter-Process communications). It's highly unlikely this one isn't compiled in.

[Muthukumar_5]

Hai,

Kernel configuration settings are updated in the .config file. Features enablement uses "y" "n" or "m". Where

y - it is enabled
n - it is not enabled
m - modularised one

By default,

COFNIG_NET
CONFIG_SYSVIPC
CONFIG_BINFMT_ELF options are enabled.

Regards,
Muthukumar.

[Jan Sladky]

hi Ming,

perhaps "sysctl -a" will also be little usefull for your purposes, for more info see man sysctl

Hope this will help you

br Jan

[Muthukumar_5]

Hai,

sysctl will be used to get the system control configuration settings. We can not ge t the kernel parameters with that.

.config file we be the source to know this. Default kernel's config will be located at /usr/src/linux-2.x.x/configs directory.
We can identify the kernel type and it's related .config file from grub loader or lilo loader.

Regards,
Muthukumar.

[Ming Zhao]

Thanks everybody!