Security-Enhanced Linux (SELinux) is a set of kernel enhancements and user-space tools to enforce mandatory access control and security policies. When SELinux is enabled on your system, there may be cases where you would like to turn off SELinux temporarily, for example when you are experimenting with Apache or NFS server, and SELinux gets in the way, blocking necessary port access.
Disable SELinux Temporarily
To disable SELinux temporarily, run the following command:
Note that you can use "echo 1 > /selinux/enforce" or "setenforce 1" to re-enable SELinux.
Disable SELinux Permanently
The above configuration will not survive the reboot. If you want to turn off SELinux permanently for good, edit /etc/selinux/config file as follows.
SELINUX=permissive (or disabled)
Finally, reboot the machine to activate the change.
Note that when you are disabling SELinux using /etc/selinux/config, there are two different options that you can use: "permissive" and "disabled". In "permissive" mode, security policies are no longer enforced, but violations are still logged. In "disabled" mode, SELinux is completely switched off, and no violation is logged.
If you cannot find /etc/selinux/config on your system, you can disable SELinux permanently by adding "selinux=0" to /boot/grub/grub.conf as follows. In this case, Grub Boot Loader will pass the kernel parameter "selinux=0" to the kernel at boot time, and SELinux will remain disabled permanently upon boot.
# grub.conf generated by anaconda # default=0 timeout=5 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu title CentOS (2.6.18-238.9.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-238.9.1.el5 ro root=LABEL=/ selinux=0 initrd /initrd-2.6.18-238.9.1.el5.img title CentOS (2.6.18-164.9.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-164.9.1.el5 ro root=LABEL=/ selinux=0 initrd /initrd-2.6.18-164.9.1.el5.img title CentOS (2.6.18-164.el5) root (hd0,0) kernel /vmlinuz-2.6.18-164.el5 ro root=LABEL=/ selinux=0 initrd /initrd-2.6.18-164.el5.img
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