Resetting or changing the root and VCF password in SDDC manager fails with the error: "passwd: Module is unknown"

Products

• VMware SDDC Manager

Issue/Introduction

• Failed to reset or change the root and VCF password through the console or SSH. 
• Changing the password using GRUB mode also fails with the following error.

Environment

VMware Cloud Foundation 5.x

Cause

 The password reset issue was caused by a misconfiguration in the /etc/pam.d/system-password file which was either absent or incorrectly set up. This resulted in the failure of the password change command.

 

Resolution

Perform the following steps to reset the password.

1. Take a snapshot of the SDDC manager appliance
2. Make a backup of the file: cp /etc/pam.d/system-password /home/vcf/
3. Replace it with the following content, the file should look exactly like the below content including the actual order of the lines:

# Begin /etc/pam.d/system-password

# use sha512 hash for encryption, use shadow, and try to use any previously
# defined authentication token (chosen password) set by any prior module

password required pam_pwquality.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=8 minclass=4 difok=4 retry=3 maxsequence=0 enforce_for_root
password required pam_pwhistory.so enforce_for_root use_authtok remember=5 retry=3
password required pam_unix.so sha512 use_authtok shadow try_first_pass

# End /etc/pam.d/system-password

    4. Reboot the SDDC manager

    5. Perform the reset of the passwords.

• • passwd vcf
  • passwd root