Add a Cinder guide

Based upon Paul's work with Swift documentation, I decided to
add a bit of Cinder documentation since Cinder isn't totally obvious.

Change-Id: I502d88200ae9fd0e8a87d9981424903be9612cd5

docs/cinder-guide.rst

@@ -0,0 +1,77 @@
+Cinder in Kolla
+===============
+
+Overview
+--------
+Currently Kolla can deploy the cinder services:
+
+- cinder-api
+- cinder-scheduler
+- cinder-backup
+- cinder-volume
+
+The cinder implementation defaults to using LVM storage.  The default
+implementation requires a volume group be set up.  This can either be
+a real physical volume or a loopback mounted file for development.
+
+Create a Volume Group
+---------------------
+Use pvcreate and vgcreate to create the volume group.  For example with
+the devices /dev/sdb and /dev/sdc:
+
+::
+
+    <WARNING ALL DATA ON /dev/sdb and /dev/sdc will be LOST!>
+
+    pvcreate /dev/sdb /dev/sdc
+    vgcreate cinder-volumes /dev/sdb /dev/sdc
+
+During development, it may be desireable to use file backed block storage.  It
+is possible to use a file and mount it as a block device via the loopback
+system.
+
+::
+
+    mknod /dev/loop2 b 7 2
+    dd if=/dev/zero of=/var/lib/cinder_data.img bs=1g count=20
+    losetup /dev/loop2 /var/lib/cinder_data.img
+    pvcreate /dev/loop2
+    vgcreate cinder-volumes /dev/loop2
+
+Validation
+----------
+
+Create a volume as follows:
+
+::
+
+    $ openstack volume create  --size 1 steak_volume
+    <bunch of stuff printed>
+
+Verify it is available.  If it says "error" here something went wrong during
+LVM creation of the volume.
+
+::
+
+    $ openstack volume list
+    +--------------------------------------+--------------+-----------+------+-------------+
+    | ID                                   | Display Name | Status    | Size | Attached to |
+    +--------------------------------------+--------------+-----------+------+-------------+
+    | 0069c17e-8a60-445a-b7f0-383a8b89f87e | steak_volume | available |    1 |             |
+    +--------------------------------------+--------------+-----------+------+-------------+
+
+Attach the volume to a server using:
+
+::
+
+    openstack server add volume steak_server 0069c17e-8a60-445a-b7f0-383a8b89f87e
+
+Check the console log added the disk:
+
+::
+
+    opoenstack console log show steak_server
+
+A /dev/vdb should appear in the console log, atleast when booting cirros.
+If the disk stays in the available state, something went wrong during the
+iSCSI mounting of the volume to the guest VM.