psql: FATAL: PAM authentication failed for user

Question

PostgreSQL 9.2.4

I cannot login anymore with a user that has worked in the past. I assume a configuration problem. So for testing I created a test user role 'testing' with the same options as the role in question (as the 'postgres' user who is still possible to login!):

CREATE ROLE testing WITH SUPERUSER NOCREATEDB NOCREATEROLE LOGIN PASSWORD 'pw';

The role was created successfully:

                                  List of roles
     Role name  |                   Attributes                   | Member of
    ------------+------------------------------------------------+-----------
     postgres   | Superuser, Create role, Create DB, Replication | {}
     testing    | Superuser                                      | {}
     ...

However, a login results in this message:

# psql -h 127.0.0.1 -p 5434 -U testing
Password for user testing:
psql: FATAL:  PAM authentication failed for user "testing"
FATAL:  PAM authentication failed for user "testing"

I also get this error when I try with the original role.

pg_hba.conf:

# "local" is for Unix domain socket connections only
local   all         all                               pam
# IPv4 local connections:
host    all         all         0.0.0.0/0             pam

Does anybody have a clue what the problem might be?

Answer 1

The main problem was that the linux user didn't exist for the database role that tried to login. There were a few other minor configuration issues as well (linux groups, rights) that needed to be fixed. Login was then possible again.