Add a doc for Cinder

Cinder is unique in that interaction with the volumes
must occur in the container as opposed to from the host.
This doc will lay out a guide for Cinder and useful
debugging tips.

Change-Id: I5cdff42ba3a40c1a20a11570649ac42a1c3aa837

docs/storage-guide.md

@@ -0,0 +1,45 @@
+# Storage Guide
+
+This is a overview of how Cinder is implemented in Kolla so that it is easier to understand how to use it. Keep in mind, this is the first iteration for Cinder as support for Ceph and physical devices will follow.
+
+## Overview
+
+Kolla's setup for Cinder uses tgtd as the default iSCSI helper to implement persistent targets.  By default, we use a loop back file that is defined by CINDER_LVM_LO_VOLUME_SIZE to create the cinder-volumes volume group.
+
+## Configure Cinder
+
+Listed below are the default configurations for Cinder.  For more info on what each variable does look at the [integration guide.](https://github.com/stackforge/kolla/blob/master/docs/integration-guide.md):
+
+    # Cinder Volume
+    CINDER_ENABLED_BACKEND=lvm57
+    CINDER_LVM_LO_VOLUME_SIZE=4G
+    CINDER_VOLUME_API_LISTEN=$HOST_IP
+    CINDER_VOLUME_BACKEND_NAME=LVM_iSCSI57
+    CINDER_VOLUME_DRIVER=cinder.volume.drivers.lvm.LVMISCSIDriver
+    CINDER_VOLUME_GROUP=cinder-volumes
+    ISCSI_HELPER=tgtadm
+    ISCSI_IP_ADDRESS=$HOST_IP
+
+## Using Cinder
+
+After you've started all you containers, you should be able to interact with Cinder.
+
+    cinder list
+
+Next, you will want to create a volume and attach it to a running instance.
+
+    cinder create 1
+    nova volume-attach <instance_id> <volume_id>
+
+## Debugging and deleting volumes
+
+The cinder-volumes volume group can't be seen from the host.  In order to interact with an existing volume, you need to jump into the Cinder Volume container.
+
+    sudo docker exec -it <cinder_volume_container> /bin/bash
+    sudo vgs
+
+Running 'vgs' will list the volumes groups.  From there, you can look at specific volumes to make sure volume creation succeeded.
+
+To delete the cinder-volumes volume group from within the container run:
+
+    sudo vgs remove cinder-volumes