外網反饋某業務失敗，查看log發現FTP連接失敗，定位發現提示密碼不對，重新修改FTP密碼后恢復正常。
但同時定位了下FTP密碼被修改的原因，發現是密碼過期了，因此查了下資料，查得修改過期時間的方法
1.vim /etc/login.defs
PASS_MAX_DAYS 99999
2.chage username -M 99999
下面是使用到的命令chage：
[root@APPServer yang]# chage --help
Usage: chage [options] [LOGIN]
Options:
-d, --lastday LAST_DAY set date of last password change to LAST_DAY
-E, --expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE
-h, --help display this help message and exit
-I, --inactive INACTIVE set password inactive after expiration
to INACTIVE
-l, --list show account aging information
-m, --mindays MIN_DAYS set minimum number of days before password
change to MIN_DAYS
-M, --maxdays MAX_DAYS set maximim number of days before password
change to MAX_DAYS
-W, --warndays WARN_DAYS set expiration warning days to WARN_DAYS
以及一個不過期的賬戶信息：
[root@APPServer yang]# chage username -l
Last password change : May 17, 2018
Password expires : never
Password inactive : never
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 99999
Number of days of warning before password expires : 7