Init script for Greenplum 4 SNMP subagent for RHEL 5 Fork it and fix it for SLES, RHEL 6. You could also get it to work with .pgpass (as mentioned in the admin guide - didn't work here, so I put them in the file).

gpsnmpd

#!/bin/sh
#
# gpsnmpd:      Provides the Greenplum SNMP as a sub-agent
#
# chkconfig: 35 99 01
# description:  gpsnmpd is the GP Software agent for SNMP
#
#

# Sanity checks.
[ -x /usr/local/greenplum-db/bin/gpsnmpd ] || exit 0

# Source function library.
. /etc/rc.d/init.d/functions

GPSNMPD_USER=gpadmin
GPSNMPD_GROUP=gpadmin
AGENTX_SOCKET=/var/agentx/master

start() {
    echo -n $"Starting Greenplum SNMP Agent: "
    AGENTX_DIRECTORY=$(dirname ${AGENTX_SOCKET})
    if [ -d ${AGENTX_DIRECTORY} ]
    then
        if [ -S  ${AGENTX_SOCKET} ]
        then
            chgrp ${GPSNMPD_GROUP} ${AGENTX_SOCKET}
            chmod g+w ${AGENTX_SOCKET}

            /bin/su - gpadmin -c '/usr/local/greenplum-db/bin/gpsnmpd -s -b -C "host=localhost dbname=postgres user=XXXXXXXX password=XXXXXXXX"'
            echo_success
        else
            echo_failure
        fi
    else
        # Note - if this is the first time snmpd has run, it's too late
        # to create the socket directory

        mkdir -p ${AGENTX_DIRECTORY}
        echo_failure
        echo "Now created agentx socket directory"
        echo "Please restart snmpd"
        echo "then start gpsnmpd"
    fi
    echo
}


stop() {
   /sbin/fuser -k /usr/local/greenplum-db/bin/gpsnmpd
}

# See how we were called.
case "$1" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    restart)
        stop
        start
        ;;
    *)
        echo $"Usage: $0 {start|stop|restart}"
        ;;
esac
exit $RETVAL