auth.log 记录大量 cron session 日志
今天在查看 auth.log 发现了大量 cron session 的日志，每隔一个小时就出现几次，看起来是定时任务在调用时以 root 用户执行而记录下来了，不过我的定时任务也没有这么频繁，不知道为什么会写入那么多记录。
Mar 5 16:17:01 *** CRON[9261]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar 5 16:17:01 *** CRON[9261]: pam_unix(cron:session): session closed for user root
Mar 5 17:17:01 *** CRON[9399]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar 5 17:17:01 *** CRON[9399]: pam_unix(cron:session): session closed for user root
Mar 5 18:17:01 *** CRON[9863]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar 5 18:17:01 *** CRON[9863]: pam_unix(cron:session): session closed for user root
Mar 5 19:17:01 *** CRON[10006]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar 5 19:17:01 *** CRON[10006]: pam_unix(cron:session): session closed for user root
网上找到了解决方法，修改以下文件
cd /etc/pam.d
sudo vim common-session-noninteractive
找到下面一行
session required pam_unix.so
然后在这一行的上面添加
session [success=1 default=ignore] pam_succeed_if.so service in cron quiet use_uid
最后重启 cron 服务
sudo service cron restart
参考
Cron: pam_unix (cron:session): session opened/closed for user root by (uid=0)