Add logging for prepare_guest

Change-Id: I2dc31acb56ee64c0c69e614a2fc96ae6b31b2ffa
diff --git a/tools/xen/build_xva.sh b/tools/xen/build_xva.sh
index c8721aa..4eb4b91 100755
--- a/tools/xen/build_xva.sh
+++ b/tools/xen/build_xva.sh
@@ -104,7 +104,7 @@
 cat <<EOF >$STAGING_DIR/etc/rc.local
 # network restart required for getting the right gateway
 /etc/init.d/networking restart
-GUEST_PASSWORD=$GUEST_PASSWORD STAGING_DIR=/ DO_TGZ=0 bash /opt/stack/devstack/tools/xen/prepare_guest.sh
+GUEST_PASSWORD=$GUEST_PASSWORD STAGING_DIR=/ DO_TGZ=0 bash /opt/stack/devstack/tools/xen/prepare_guest.sh > /opt/stack/prepare_guest.log 2>&1
 su -c "/opt/stack/run.sh > /opt/stack/run.sh.log" stack
 exit 0
 EOF
diff --git a/tools/xen/prepare_guest.sh b/tools/xen/prepare_guest.sh
index 2f19b9d..77ce54a 100644
--- a/tools/xen/prepare_guest.sh
+++ b/tools/xen/prepare_guest.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -x
+
 # Configurable nuggets
 GUEST_PASSWORD=${GUEST_PASSWORD:-secrete}
 STAGING_DIR=${STAGING_DIR:-stage}