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In one of my customers Linux box with CentOS 6.0 installed, I found that the user root is prohibited to alter any kernel parameters also editing the /etc/sysctl.conf throws permission denied.

In sudoers list root is given full access.

root    ALL=(ALL) ALL

I was unable to figure out what could prevent root from changing the values.

What can cause the root user to prevent doing any change in the kernel parameters ?

share|improve this question
What error message is given when the root user tries to make a sysctl change? /etc/sudoers should have NO impact on the root user's privileges. – ewwhite Mar 7 '12 at 7:42
I am getting "Operation not permitted" error. – Supratik Mar 7 '12 at 7:48
What command are you running? – ewwhite Mar 7 '12 at 7:55
I tried both the commands 1. sysctl -w kernel.core_pattern=core.%e.%p 2. echo "core.%e.%p" > /proc/sys/kernel/core_pattern and both returned the same error. – Supratik Mar 7 '12 at 7:57
Is selinux or grsec enabled? – HampusLi Mar 7 '12 at 9:30

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