查看cron运行日志
tail -f /var/log/cron
报如下错误：
May 8 10:14:01 localhost crond[9399]: (root) FAILED to authorize user with PAM (Module is unknown)
May 8 10:14:01 localhost crond[9400]: (root) FAILED to authorize user with PAM (Module is unknown)
网上有如下解决方法：
- 修改/etc/pam.d/crond，把把所有required改成sufficient，这个可能对非root用户管用。
#
# The PAM configuration file for the cron daemon
#
#
# No PAM authentication called, auth modules not needed
account required pam_access.so
account include password-auth
session required pam_loginuid.so
session include password-auth
auth include password-auth
最终解决办法：
重启crond服务
/etc/init.d/crond restart