@@ -30,18 +30,19 @@ if ! grep -q natty /etc/lsb-release; then

     fi

 fi

+# Keep track of the current devstack directory.

+TOP_DIR=$(cd $(dirname "$0") && pwd)

+

 # stack.sh keeps the list of **apt** and **pip** dependencies in external

 # files, along with config templates and other useful files.  You can find these

 # in the ``files`` directory (next to this script).  We will reference this

 # directory using the ``FILES`` variable in this script.

-FILES=`pwd`/files

+FILES=$TOP_DIR/files

 if [ ! -d $FILES ]; then

     echo "ERROR: missing devstack/files - did you grab more than just stack.sh?"

     exit 1

 fi

-# Keep track of the current devstack directory.

-TOP_DIR=$(cd $(dirname "$0") && pwd)

 # OpenStack is designed to be run as a regular user (Dashboard will fail to run

 # as root, since apache refused to startup serve content from root user).  If

@@ -292,6 +293,8 @@ sudo PIP_DOWNLOAD_CACHE=/var/cache/pip pip install `cat $FILES/pips/*`

 function git_clone {

     # if there is an existing checkout, move it out of the way

     if [[ "$RECLONE" == "yes" ]]; then

+        # FIXME(ja): if we were smarter we could speed up RECLONE by

+        # using the old git repo as the basis of our new clone...

         if [ -d $2 ]; then

             mv $2 /tmp/stack.`date +%s`

         fi

@@ -408,6 +411,8 @@ if [[ "$ENABLED_SERVICES" =~ "dash" ]]; then

     # ``local_settings.py`` is used to override dashboard default settings.

     cp $FILES/dash_settings.py $DASH_DIR/openstack-dashboard/local/local_settings.py

+    # Initialize the dashboard database (it stores sessions and notices shown to

+    # users).  The user system is external (keystone).

     cd $DASH_DIR/openstack-dashboard

     dashboard/manage.py syncdb

@@ -435,7 +440,8 @@ if [[ "$ENABLED_SERVICES" =~ "g-reg" ]]; then

     # (re)create glance database

     mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'DROP DATABASE IF EXISTS glance;'

     mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'CREATE DATABASE glance;'

-    # Copy over our glance-registry.conf

+

+    # Copy over our glance configurations and update them

     GLANCE_CONF=$GLANCE_DIR/etc/glance-registry.conf

     cp $FILES/glance-registry.conf $GLANCE_CONF

     sudo sed -e "s,%SQL_CONN%,$BASE_SQL_CONN/glance,g" -i $GLANCE_CONF

@@ -454,7 +460,7 @@ fi

 # We are going to use the sample http middleware configuration from the keystone

 # project to launch nova.  This paste config adds the configuration required

 # for nova to validate keystone tokens - except we need to switch the config

-# to use our admin token instead (instead of the token from their sample data).

+# to use our service token instead (instead of the invalid token 999888777666).

 sudo sed -e "s,999888777666,$SERVICE_TOKEN,g" -i $KEYSTONE_DIR/examples/paste/nova-api-paste.ini

 if [[ "$ENABLED_SERVICES" =~ "n-cpu" ]]; then

@@ -465,9 +471,9 @@ if [[ "$ENABLED_SERVICES" =~ "n-cpu" ]]; then

     # attempt to load modules: network block device - used to manage qcow images

     sudo modprobe nbd || true

-    # Check for kvm (hardware based virtualization).  If unable to load kvm, 

-    # set the libvirt type to qemu.  Note: many systems come with hardware 

-    # virtualization disabled in BIOS.

+    # Check for kvm (hardware based virtualization).  If unable to initialize 

+    # kvm, we drop back to the slower emulation mode (qemu).  Note: many systems 

+    # come with hardware virtualization disabled in BIOS.

     if [[ "$LIBVIRT_TYPE" == "kvm" ]]; then

         sudo modprobe kvm || true

         if [ ! -e /dev/kvm ]; then

@@ -481,7 +487,8 @@ if [[ "$ENABLED_SERVICES" =~ "n-cpu" ]]; then

     # to simulate multiple systems.

     if [[ "$LIBVIRT_TYPE" == "lxc" ]]; then

         sudo apt-get install lxc -y

-        # lxc requires cgroups to be configured on /cgroup

+        # lxc uses cgroups (a kernel interface via virtual filesystem) configured

+        # and mounted to ``/cgroup``

         sudo mkdir -p /cgroup

         if ! grep -q cgroup /etc/fstab; then

             echo none /cgroup cgroup cpuacct,memory,devices,cpu,freezer,blkio 0 0 | sudo tee -a /etc/fstab

@@ -491,9 +498,12 @@ if [[ "$ENABLED_SERVICES" =~ "n-cpu" ]]; then

         fi

     fi

-    # User needs to be member of libvirtd group for nova-compute to use libvirt.

+    # The user that nova runs as needs to be member of libvirtd group otherwise

+    # nova-compute will be unable to use libvirt.

     sudo usermod -a -G libvirtd `whoami`

-    # if kvm wasn't running before we need to restart libvirt to enable it

+    # libvirt detects various settings on startup, as we potentially changed 

+    # the system configuration (modules, filesystems), we need to restart

+    # libvirt to detect those changes.

     sudo /etc/init.d/libvirt-bin restart

@@ -503,12 +513,14 @@ if [[ "$ENABLED_SERVICES" =~ "n-cpu" ]]; then

     # Nova stores each instance in its own directory.

     mkdir -p $NOVA_DIR/instances

-    # if there is a partition labeled nova-instances use it (ext filesystems

-    # can be labeled via e2label)

-    ## FIXME: if already mounted this blows up...

+    # You can specify a different disk to be mounted and used for backing the

+    # virtual machines.  If there is a partition labeled nova-instances we 

+    # mount it (ext filesystems can be labeled via e2label).

     if [ -L /dev/disk/by-label/nova-instances ]; then

-        sudo mount -L nova-instances $NOVA_DIR/instances

-        sudo chown -R `whoami` $NOVA_DIR/instances

+        if ! mount -n | grep -q nova-instances; then

+            sudo mount -L nova-instances $NOVA_DIR/instances

+            sudo chown -R `whoami` $NOVA_DIR/instances

+        fi

     fi

     # Clean out the instances directory.