在配置nfs服务器，设定selinux时，碰到了SELinux: Could not downgrade policy file的错误提示，下文是其解决方案。
一、故障现象
[root@system1 ~]# semanage fcontext -a -t 'public_content_t' '/protected(/.*)?' SELinux: Could not downgrade policy file /etc/selinux/targeted/policy/policy.29, searching for an older version. SELinux: Could not open policy file <= /etc/selinux/targeted/policy/policy.29: No such file or directory /sbin/load_policy: Can't load policy: No such file or directory libsemanage.semanage_reload_policy: load_policy returned error code 2. SELinux: Could not downgrade policy file /etc/selinux/targeted/policy/policy.29, searching for an older version. SELinux: Could not open policy file <= /etc/selinux/targeted/policy/policy.29: No such file or directory /sbin/load_policy: Can't load policy: No such file or directory libsemanage.semanage_reload_policy: load_policy returned error code 2. ValueError: Could not commit semanage transaction
二、解决方案
从故障的提示来看，说不能够降级策略文件，以及找不到policy.29这个文件 [root@system1 ~]# more /etc/redhat-release Red Hat Enterprise Linux Server release 7.0 (Maipo) [root@system1 ~]# uname -r 3.10.0-123.el7.x86_64 ###下面查看selinux配置，如下，为disabled状态 [root@system1 ~]# sestatus SELinux status: disabled [root@system1 ~]# getenforce Disabled [root@system1 ~]# rpm -q libsepol libsemanage libselinux libsepol-2.1.9-3.el7.x86_64 libsemanage-2.1.10-16.el7.x86_64 libselinux-2.2.2-6.el7.x86_64 ### 临时修改selinux 配置 [root@system1 ~]# setenforce 1 ###尝试设置为1，依旧提示关闭 setenforce: SELinux is disabled [root@system1 ~]# getenforce Disabled ### 查看enforce配置文件 [root@system1 ~]# more /etc/sysconfig/selinux # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. #SELINUX=permissive SELINUX=disabled # SELINUXTYPE= can take one of these two values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted ### 手工修改配置文件 [root@system1 ~]# vi /etc/sysconfig/selinux SELINUX=enforce [root@system1 ~]# getenforce ###依旧为关闭 Disabled ###不知道什么原因导致配置修改无法生效，于是尝试重启Linux [root@system1 ~]# reboot ### 再次修改和执行都OK [root@system1 ~]# getenforce Permissive [root@system1 ~]# [root@system1 ~]# [root@system1 ~]# setenforce 1 [root@system1 ~]# [root@system1 ~]# getenforce Enforcing ### 再次执行semanage成功 [root@system1 ~]# semanage fcontext -a -t 'public_content_t' '/protected(/.*)?' [root@system1 ~]#