I am using linux Red Hat 8 OS, it may be 2 old now, ^_^ I have just installed my opennms by rpm package, and now i am running the installer to setup the PostgreSQL database: # $OPENNMS_HOME/bin/install -disU but some exception happens: ============================================================================== OpenNMS Installer Version $Id: Installer.java 3056 2006-03-26 19:39:16Z djgregor $ ============================================================================== Configures PostgreSQL tables, users, and other miscellaneous settings. Exception in thread "main" org.postgresql.util.PSQLException: Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections. at org.postgresql.jdbc1.AbstractJdbc1Connection.openConnection(AbstractJdbc1Connection.java:204) at org.postgresql.Driver.connect(Driver.java:139) at java.sql.DriverManager.getConnection(Unknown Source) at java.sql.DriverManager.getConnection(Unknown Source) at org.opennms.install.Installer.databaseConnect(Installer.java:613) at org.opennms.install.Installer.install(Installer.java:195) at org.opennms.install.Installer.main(Installer.java:2450) i have just now checked my postgre with command "netstat -anp | grep "post"" and they are right: udp 0 0 127.0.0.1:32968 127.0.0.1:32968 ESTABLISHED 5850/postmaster unix 2 [ ACC ] STREAM LISTENING 123166 5850/postmaster /tmp/.s.PGSQL.5432 why dont my opennms setup datebase successfully on my postgresql?