1. vi /etc/pam.d/system-auth as root.

2. Look for the following two lines:

   password    requisite     pam_cracklib.so try_first_pass retry=3password    sufficient    pam_unix.so md5 shadow nullok try_first_pass use_authtok

3. Comment out the first of the two lines:

   #password    requisite     pam_cracklib.so try_first_pass retry=3

4. Remove use_authtok on the second line. Otherwise you’ll get “passwd: Authentication information cannot be recovered” error.

   password    sufficient    pam_unix.so md5 shadow nullok try_first_pass

linux 用简单密码