If a single CENTOS user changes the password, the message "passwd: Authentication Token Manipulation Er" is returned.

In CENTOS, if a single user changes the password, "passwd: Authentication Token Manipulation Error" is reported. Before a CentOS 5.3 WEB server is resolved, the key can be used for ssh remote connection, suddenly one day, remote connection fails. The specific phenomenon is: a) no response is returned when a key is connected through SecureCRT; B) a password or user name error is reported when a direct password connection occurs; c) "Connection closed by 10.10.10.100"; d) When you log on to the local console, enter the user name and report "login incorrec ". It can be confirmed that no one has changed the password before. The specific solution process is as follows: 1. enter the system in single-user mode locally. directly report "passwd: Authentication Token Manipulation Error" In passwd. After searching for this Error, there are multiple solutions on the Internet. For details, refer to the final part of this article. I have tried these methods and it does not take effect. 3. # When df-hl is found, the root file system is full. After some space is cleared, the above error is still reported when passwd changes the password. 4. view the/var/log/secure log. The following error is found: Nov 26 05:16:46 rcwweb2 sshd [1065]: PAM unable to dlopen (/lib/security/pam_unix.so) nov 26 05:16:46 rcwweb2 sshd [1065]: PAM [error:/lib/security/pam_unix.so: invalid ELF header] Nov 26 05:16:46 rcwweb2 sshd [1065]: PAM adding faulty module: /lib/security/pam_unix.soNov 26 05:16:46 rcwweb2 sshd [1066]: fatal: Access de Nied for user root by PAM account configurationp5. the log shows that the/lib/security/pam_unix.so file is faulty. Previously, the local machine had a pam_unix.so.bak file. After deleting the damaged file and restoring the backup, you can log on normally. I don't know if this file is damaged because the root disk is full. During this period, refer to some methods for handling the Error "passwd: Authentication Token Manipulation Error" on the Internet, as shown in the following code: 1) the possible cause is that the/etc/passwd and/etc/shadow files are not synchronized, And the pwconv command is used for synchronization; 2) the/etc/passwd and/etc/shadow security settings are set, use chattr-I/etc/passwd/etc/shadow. 3) use echo "123456" | passwd -- stdin root or echo "root: lanmang" | chpasswd to manually change the password; 4) Disable selinux solution; 5) Use perl-e 'print crypt ("passw0rd", "\ $1 \ $ YkRDae. B \ $ ")," \ n "'manually generate the password string and copy it to the/etc/shadow file;