Проблемы с настройкой VNC-сессии для RHEL 7 на Power8

Я следую за http://www.linuxexplorers.com/2014/04/configure-vnc-server-in-red-hat-enterprise-linux-7-rhel7/ для настройки VNC-сервера RHEL 7.

На последнем этапе настройки "systemctl start vncserver@:1.service" я получил

Job for vncserver@:1.service failed. See 'systemctl status vncserver@:1.service' and 'journalctl -xn' for details. 

journalctl -xn 
-- Logs begin at Tue 2014-09-02 14:17:21 CDT, end at Tue 2014-09-02 15:28:53 CDT. -- 
Sep 02 15:28:53 xx.xx.xx.com systemd[1]: Started Session c2 of user zzz. 
-- Subject: Unit session-c2.scope has finished start-up 
-- Defined-By: systemd 
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel 
-- 
-- Unit session-c2.scope has finished starting up. 
-- 
-- The start-up result is done. 
Sep 02 15:28:53 xx.xx.xx.com runuser[42609]: pam_unix(runuser-l:session): session opened for user yyy 
Sep 02 15:28:53 xx.xx.xx.com runuser[42609]: Warning: xx.xx.xx.com:1 is taken because of /tmp 
Sep 02 15:28:53 xx.xx.xx.com runuser[42609]: Remove this file if there is no X server xx.xx.xx.com
Sep 02 15:28:53 xx.xx.xx.com runuser[42609]: A VNC server is already running as :1 
Sep 02 15:28:53 xx.xx.xx.com runuser[42609]: pam_unix(runuser-l:session): session closed for user yyy 
Sep 02 15:28:53 xx.xx.xx.com systemd[1]: vncserver@:1.service: control process exited, code=exited s 
Sep 02 15:28:53 xx.xx.xx.com systemd[1]: Failed to start Remote desktop service (VNC). 
-- Subject: Unit vncserver@:1.service has failed 
-- Defined-By: systemd 
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel 
-- 
-- Unit vncserver@:1.service has failed. 
-- 
-- The result is failed. 
Sep 02 15:28:53 xx.xx.xx.com systemd[1]: Unit vncserver@:1.service entered failed state. 
Sep 02 15:28:53 xx.xx.xx.com systemd[1]: Failed to mark scope session-c2.scope as abandoned : Stale