Adds Volume Count and Dynamic Reload

Adds a volume_count parameter that allows the user to
change the number of volumes.  Test execution still
uses each volume specified and appends it to the host
ip address in the graphite metrics.

Changes the cache policy of the stack from SNAPS-OO
so that changes made to the stack are refelcted in
StorPerf.

Fixes the documentation path and updates the docs
for the above changes.

Change-Id: I5b9160b469e80d4f7d6906ac270bb3b75411fb5a
JIRA: STORPERF-242
Signed-off-by: mbeierl <mark.beierl@dell.com>

1 files changed, 40 insertions, 6 deletions

diff --git a/docs/testing/user/test-usage.rst b/docs/testing/user/test-usage.rst
index 8048cff..78bee4e 100644
--- a/docs/testing/user/test-usage.rst
+++ b/docs/testing/user/test-usage.rst
@@ -36,16 +36,31 @@ Configure The Environment
 
 The following pieces of information are required to prepare the environment:
 
-- The number of VMs/Cinder volumes to create
-- The Glance image that holds the VM operating system to use.  StorPerf has
-  only been tested with Ubuntu 16.04
-- The OpenStack flavor to use when creating the VMs
-- The name of the public network that agents will use
-- The size, in gigabytes, of the Cinder volumes to create
+- The number of VMs/Cinder volumes to create.
+- The Glance image that holds the VM operating system to use.
+- The OpenStack flavor to use when creating the VMs.
+- The name of the public network that agents will use.
+- The size, in gigabytes, of the Cinder volumes to create.
+- The number of the Cinder volumes to attach to each VM.
 - The availability zone (optional) in which the VM is to be launched. Defaults to **nova**.
 - The username (optional) if we specify a custom image.
 - The password (optional) for the above image.
 
+**Note**: on ARM based platforms there exists a bug in the kernel which can prevent
+VMs from properly attaching Cinder volumes.  There are two known workarounds:
+
+#. Create the environment with 0 Cinder volumes attached, and after the VMs
+  have finished booting, modify the stack to have 1 or more Cinder volumes.
+  See section on Changing Stack Parameters later in this guide.
+#. Add the following image metadata to Glance.  This will cause the Cinder
+  volume to be mounted as a SCSI device, and therefore your target will be
+  /dev/sdb, etc, instead of /dev/vdb.  You will need to specify this in your
+  warm up and workload jobs.
+
+.. code-block:
+  --property hw_disk_bus=scsi --property hw_scsi_model=virtio-scsi
+
+
 The ReST API is a POST to http://StorPerf:5000/api/v1.0/configurations and
 takes a JSON payload as follows.
 
@@ -57,6 +72,7 @@ takes a JSON payload as follows.
      "agent_image": string,
      "public_network": string,
      "volume_size": int,
+     "volume_count": int,
      "availability_zone": string,
      "username": string,
      "password": string
@@ -165,6 +181,24 @@ is required in order to push results to the OPNFV Test Results DB:
           "test_case": "snia_steady_state"
       }
 
+Changing Stack Parameters
+~~~~~~~~~~~~~~~~~~~~~~~~~
+While StorPerf currently does not support changing the parameters of the
+stack directly, it is possible to change the stack using the OpenStack client
+library.  The following parameters can be changed:
+
+- agent_count: to increase or decrease the number of VMs.
+- volume_count: to change the number of Cinder volumes per VM.
+- volume_size: to increase the size of each volume.  Note: Cinder cannot shrink volumes.
+
+Increasing the number of agents or volumes, or increasing the size of the volumes
+will require you to kick off a new _warm_up job to initialize the newly
+allocated volumes.
+
+The following is an example of how to change the stack using the heat client:
+
+.. code-block::
+  heat stack-update StorPerfAgentGroup --existing -P "volume_count=2"
 
 
 Query Jobs Information