This way:

<target name="start-a-domain" if="a.domain.exists" unless="skip.domain" depends="check.domain.exists"> <property name="a.domain.name" value="${default.domain}"/><!-- convenience default --> <echo message="STARTING domain ${a.domain.name}..." /> <echo message="stuff.dir ${stuff.dir}..." /> <exec executable="${gf.install.home}/bin/asadmin.bat" os="Windows XP,Windows 2000,Windows 2003" dir="${stuff.dir}" spawn="true" failonerror="false"> <arg value="start-domain"/> <arg value="--user"/> <arg value="admin"/> <arg value="--passwordfile"/> <arg value="password.txt"/> <arg value="${a.domain.name}"/> </exec> <exec executable="${gf.install.home}/bin/asadmin" dir="${stuff.dir}" os="SunOS,Linux,AIX,Mac OS X"> <arg line="start-domain --user admin --passwordfile password.txt ${a.domain.name}"/> </exec> <echo message="STARTED domain ${a.domain.name}..." /> </target>

(start-domain command seemed not to be obligatory with user and passwd data but stop-domain did when file-user was added etc. So we include it for start too.) This worked reliably unless some integration fault prevented proper start due to bundling error or start failure of some essential service.