How do I recreate a missing shadow entry?

Question

How can I recreate a user in my /etc/shadow file?

Answer

Restoring from a backup is the best solution; however, using the 'chage' command can create an entry for the user in /etc/shadow file.

Note: In the commands below, substitute $user for the username you wish to use.

1. Access your server using SSH as the root user.

2. Verify that the user does not have a shadow entry by running the getent command against it. No output confirms the user is missing:

   # getent shadow $user

3. If the user is confirmed missing, use chage to create the shadow file entry:

   # chage -m 0 $user

4. You can use getent as described in step 2 to confirm the entry was created successfully.