password authentication failed for user "postgres"

postgresql安裝好後用pgadmin連接出現如下的錯誤訊息：

Error connecting to the server:FATAL: password authentication failed for user "postgres"  

錯誤原因是沒有設定postgres的密碼，檢查及設定如下：

[root@Vigor14 ~]# su -l postgres -bash-3.2$ psql psql (8.4.7) Type "help" for help.  postgres=# select * from pg_shadow;  usename  | usesysid | usecreatedb | usesuper | usecatupd | passwd | valunti l | useconfig  ----------+----------+-------------+----------+-----------+--------+-------- --+-----------  postgres |       10 | t           | t        | t         |        |           |  (1 row)  postgres=# alter user postgres with password 'postgres'; ALTER ROLE postgres=#