SymptomNPS did not start. To get a better understanding of how much progress nzstart made before exiting, you ran the following two commands:nzstart –itail -f /nz/kit/log/postgres/pg.logThe following output appeared:2009-08-25 06:34 EDT 30640 DEBUG: connection failed: host=127.0.0.1 user=ADMIN database=SYSTEM error=No pghba.conf entry for host localhost, user ADMIN, database SYSTEM2009-08-25 06:88 EDT 30640 DEBUG: connection failed: host=127.0.0.1 user=ADMIN database=SYSTEM error=No pghba.conf entry for host localhost, user ADMIN, database SYSTEM. Resolving The ProblemFor nzstart to make a connection to the database, the following line must be in the /nz/data/pghba.conf file:# NZ - we need to allow trusted admin commands to connect freely when# run as the db owner. We enforce security by making sure the unix# socket file is writable ONLY by the db owner.

See postgresql.conf,# where we set unixsocketpermissions = 0700.local all trustIn addition, the pghba.conf file must be readable by the nz user. The expected permissions of this file are as follows:-rw- 1 nz nz 8543 Aug 25 06:53 pghba.conf.

Client access and authentication is controlled by a configuration file named pghba.conf (the standard PostgreSQL host-based authentication file). Newest 'google toolbox for mac questions and answers. For detailed information about this file, see The pghba.conf File in the PostgreSQL documentation. In Greenplum Database, the pghba.conf file of the master instance controls client access and authentication to your Greenplum system.