sqlplus: error while loading shared libraries: /u0

sqlplus: error while loading shared libraries: /u01/app/oracle/product/11.1.0/db_1/lib/libnnz11.so: cannot restore segment prot after reloc: Permission denied

Immediately after a successful RDBMS installation (perhaps even including a sample DB instance creation), sqlplus will not start:

[oracle@test ~]$ sqlplus ‘/as sysdba’
sqlplus: error while loading shared libraries: /u01/app/oracle/product/11.1.0/db_1/lib/libnnz11.so: cannot restore segment prot after reloc: Permission denied

The reason is that SELinux is running in “enforcing” mode.

You can check it on file /etc/pam.d/login

Oracle development has recommended the following workaround while they correct the problem:

Switch SELinux from the default “Enforcing” mode that it is running in, to the “Permissive” mode.

Commands, as root:
======================
getenforce       (returns “Enforcing”)
setenforce 0
getenforce       (returns “Permissive”)

This allows SELinux to continue running, and logging denial messages, but SELinux will not actually deny any operations. Once Development has resolved this issue, you can (and should) return SELinux to the default “Enforcing” mode as follows:

Commands, as root:
======================
setenforce 1
getenforce       (returns “Enforcing”)