..
      Copyright 2016 Hitachi Data Systems, Inc.
      All Rights Reserved.

      Licensed under the Apache License, Version 2.0 (the "License"); you may
      not use this file except in compliance with the License. You may obtain
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           http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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      under the License.

=======================================================
Hitachi NAS Platform File Services Driver for OpenStack
=======================================================
------------------
Driver Version 3.0
------------------

Hitachi NAS Platform Storage Requirements
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This Hitachi NAS Platform File Services Driver for OpenStack provides support
for Hitachi NAS Platform (HNAS) models 3080, 3090, 4040, 4060, 4080 and 4100
with NAS OS 12.2 or higher.
Before configuring the driver, ensure the HNAS has at least:

- 1 storage pool (span) configured.
- 1 EVS configured.
- 1 file system in this EVS, created without replication target option and
  should be in mounted state. It is recommended to disable auto-expansion,
  because the scheduler uses the current free space reported by the file
  system when creating shares.
- 1 Management User configured with "supervisor" permission level.
- Hitachi NAS Management interface should be reachable from manila-share
  node.

Also, if the driver is going to create CIFS shares, either LDAP servers or
domains must be configured previously in HNAS to provide the users and groups.

Supported Operations
~~~~~~~~~~~~~~~~~~~~

The following operations are supported in this version of Hitachi NAS Platform
File Services Driver for OpenStack:

- Create and delete CIFS and NFS shares;
- Extend and shrink shares;
- Manage rules to shares (allow/deny access);
- Allow and deny share access;

  - ``IP`` access type supported for ``NFS`` shares;
  - ``User`` access type supported for ``CIFS`` shares;
  - Both ``RW`` and ``RO`` access level are supported for NFS and CIFS shares;
- Manage and unmanage shares;
- Create and delete snapshots;
- Create shares from snapshots.

Driver Configuration
~~~~~~~~~~~~~~~~~~~~

This document contains the installation and user guide of the Hitachi NAS
Platform File Services Driver for OpenStack. Although mentioning some Shared
File Systems service operations and HNAS commands, both are not in the scope of
this document. Please refer to their own guides for details.

Before configuring the driver, make sure that the nodes running the
manila-share service have access to the HNAS management port, and compute and
network nodes have access to the data ports (EVS IPs or aggregations).

The driver configuration can be summarized in the following steps:

#. Configure HNAS parameters on ``manila.conf``;
#. Prepare the network ensuring all OpenStack-HNAS connections mentioned above;
#. Configure/create share type;
#. Restart the services;
#. Configure OpenStack networks.

Step 1 - HNAS Parameters Configuration
**************************************

The following parameters need to be configured in the [DEFAULT] section
of ``/etc/manila/manila.conf``:

+----------------------------+------------------------------------------------+
|          **Option**        |               **Description**                  |
+============================+================================================+
| enabled_share_backends     | Name of the section on ``manila.conf`` used to |
|                            | specify a backend. For example:                |
|                            | *enabled_share_backends = hnas1*               |
+----------------------------+------------------------------------------------+
| enabled_share_protocols    | Specify a list of protocols to be allowed for  |
|                            | share creation. This driver version supports   |
|                            | NFS and/or CIFS.                               |
+----------------------------+------------------------------------------------+

The following parameters need to be configured in the [backend] section
of ``/etc/manila/manila.conf``:

+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
|                  **Option**                     |                                          **Description**                                            |
+=================================================+=====================================================================================================+
| share_backend_name                              | A name for the backend.                                                                             |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| share_driver                                    | Python module path. For this driver **this must be**:                                               |
|                                                 | *manila.share.drivers.hitachi.hnas.driver.HitachiHNASDriver*                                        |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| driver_handles_share_servers                    | Driver working mode. For this driver **this must be**:                                              |
|                                                 | *False*.                                                                                            |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_ip                                 | HNAS management interface IP for communication between manila-share node and HNAS.                  |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_user                               | This field is used to provide user credential to HNAS. Provided management user must have           |
|                                                 | "supervisor" level.                                                                                 |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_password                           | This field is used to provide password credential to HNAS.                                          |
|                                                 | Either hitachi_hnas_password or hitachi_hnas_ssh_private_key must be set.                           |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_ssh_private_key                    | Set this parameter with RSA/DSA private key path to allow the driver to connect into HNAS.          |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_evs_id                             | ID from EVS which this backend is assigned to (ID can be listed by CLI "evs list"                   |
|                                                 | or EVS Management in HNAS Interface).                                                               |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_evs_ip                             | EVS IP for mounting shares (this can be listed by CLI "evs list" or EVS Management in HNAS          |
|                                                 | interface).                                                                                         |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_file_system_name                   | Name of the file system in HNAS, located in the specified EVS.                                      |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_cluster_admin_ip0*                 | If HNAS is in a multi-farm (one SMU managing multiple HNAS) configuration, set this parameter with  |
|                                                 | the IP of the cluster's admin node.                                                                 |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_stalled_job_timeout*               | Tree-clone-job commands are used to create snapshots and create shares from snapshots.              |
|                                                 | This parameter sets a timeout (in seconds) to wait for jobs to complete. Default value is           |
|                                                 | 30 seconds.                                                                                         |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_driver_helper*                     | Python module path for the driver helper. For this driver, it should use (default value):           |
|                                                 | *manila.share.drivers.hitachi.hnas.ssh.HNASSSHBackend*                                              |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| hitachi_hnas_allow_cifs_snapshot_while_mounted* | By default, CIFS snapshots are not allowed to be taken while the share has clients connected        |
|                                                 | because point-in-time replica cannot be guaranteed for all files. This parameter can be set         |
|                                                 | to *True* to allow snapshots to be taken while the share has clients connected. **WARNING**:        |
|                                                 | Setting this parameter to *True* might cause inconsistent snapshots on CIFS shares. Default         |
|                                                 | value is *False*.                                                                                   |
+-------------------------------------------------+-----------------------------------------------------------------------------------------------------+

\* Non mandatory parameters.

Below is an example of a valid configuration of HNAS driver:

.. code-block:: ini

   [DEFAULT]``
   ...
   enabled_share_backends = hitachi1
   enabled_share_protocols = CIFS,NFS
   ...

   [hitachi1]
   share_backend_name = HITACHI1
   share_driver = manila.share.drivers.hitachi.hnas.driver.HitachiHNASDriver
   driver_handles_share_servers = False
   hitachi_hnas_ip = 172.24.44.15
   hitachi_hnas_user = supervisor
   hitachi_hnas_password = supervisor
   hitachi_hnas_evs_id = 1
   hitachi_hnas_evs_ip = 10.0.1.20
   hitachi_hnas_file_system_name = FS-Manila

Step 2 - Prepare the Network
****************************

In the driver mode used by Hitachi NAS Platform File Services Driver for
OpenStack, driver_handles_share_servers (DHSS) as False, the driver does not
handle network configuration, it is up to the administrator to configure it.
It is mandatory that HNAS management interface is reachable from a manila-share
node through admin network, while the selected EVS data interface is reachable
from OpenStack Cloud, such as through neutron flat networking. Here is a
step-by-step of an example configuration:

| **Manila-Share Node:**
| **eth0**: Admin Network, can ping HNAS management interface.
| **eth1**: Data Network, can ping HNAS EVS IP (data interface). This interface
 is only required if you plan to use Share Migration.

| **Network Node and Compute Nodes:**
| **eth0**: Admin Network, can ping HNAS management interface.
| **eth1**: Data Network, can ping HNAS EVS IP (data interface).

The following image represents the described scenario:

.. image:: /images/rpc/hds_network.jpg
   :width: 60%

Run in **Network Node**:

.. code-block:: console

   $ sudo ifconfig eth1 0
   $ sudo ovs-vsctl add-br br-eth1
   $ sudo ovs-vsctl add-port br-eth1 eth1
   $ sudo ifconfig eth1 up

Edit */etc/neutron/plugins/ml2/ml2_conf.ini* (default directory), change the
following settings as follows in their respective tags:

.. code-block:: ini

   [ml2]
   type_drivers = flat,vlan,vxlan,gre
   mechanism_drivers = openvswitch

   [ml2_type_flat]
   flat_networks = physnet1,physnet2

   [ml2_type_vlan]
   network_vlan_ranges = physnet1:1000:1500,physnet2:2000:2500

   [ovs]
   bridge_mappings = physnet1:br-ex,physnet2:br-eth1

You may have to repeat the last line above in another file in the Compute Node,
if it exists is located in: */etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini*.

Create a route in HNAS to the tenant network. Please make sure
multi-tenancy is enabled and routes are configured per EVS. Use the command
"route-net-add" in HNAS console, where the network parameter should be the
tenant's private network, while the gateway parameter should be the flat
network gateway and the "console-context --evs" parameter should be the ID of
EVS in use, such as in the following example:

.. code-block:: console

   $ console-context --evs 3 route-net-add --gateway 192.168.1.1 10.0.0.0/24

Step 3 - Share Type Configuration
*********************************

Shared File Systems service requires that the share type includes the
driver_handles_share_servers extra-spec. This ensures that the share will be
created on a backend that supports the requested driver_handles_share_servers
capability. For the Hitachi NAS Platform File Services Driver for OpenStack
this must be set to False.

.. code-block:: console

   $ manila type-create hitachi False

Additionally, the driver also reports the following common capabilities that
can be specified in the share type:

+----------------------------+----------------------------------------------+
|        **Capability**      |             **Description**                  |
+============================+==============================================+
| thin_provisioning = True   | All shares created on HNAS are always thin   |
|                            | provisioned. So, if you set it, the value    |
|                            | **must be**: *True*.                         |
+----------------------------+----------------------------------------------+
| dedupe = True/False        | HNAS supports deduplication on its file      |
|                            | systems and the driver will report           |
|                            | *dedupe=True* if it is enabled on the file   |
|                            | system being used. To use it, go to HNAS and |
|                            | enable the feature on the file system used.  |
+----------------------------+----------------------------------------------+

To specify a common capability on the share type, use the *type-key* command,
for example:

.. code-block:: console

   $ manila type-key hitachi set dedupe=True

Step 4 - Restart the Services
*****************************

Restart all Shared File Systems services (manila-share, manila-scheduler and
manila-api) and neutron services (neutron-\*). This step is specific to your
environment. If you are running in devstack for example, you have to log into
screen (``screen -r``), stop the process (``Ctrl^C``) and run it again. If you
are running it in a distro like RHEL, a systemd command (for example
*systemctl restart manila-api*) is used to restart the service.

Step 5 - Configure OpenStack Networks
*************************************

In Neutron Controller it is necessary to create a network, a subnet and to add
this subnet interface to a router:

Create a network to the given tenant (demo), providing the DEMO_ID (this can be
fetched using *keystone tenant-list*), a name for the network, the name of the
physical network over which the virtual network is implemented and the type of
the physical mechanism by which the virtual network is implemented:

.. code-block:: console

   $ neutron net-create --tenant-id <DEMO_ID> hnas_network
   --provider:physical_network=physnet2 --provider:network_type=flat

Create a subnet to same tenant (demo), providing the DEMO_ID (this can be fetched
using *keystone tenant-list*), the gateway IP of this subnet, a name for the
subnet, the network ID created on previously step (this can be fetched using
*neutron net-list*) and CIDR of subnet:

.. code-block:: console

   $ neutron subnet-create --tenant-id <DEMO_ID> --gateway <GATEWAY>
   --name hnas_subnet <NETWORK_ID> <SUBNET_CIDR>

Finally, add the subnet interface to a router, providing the router ID and
subnet ID created on previously step (can be fetched using *neutron subnet-list*):

.. code-block:: console

   $ neutron router-interface-add <ROUTER_ID> <SUBNET_ID>

Manage and Unmanage Shares
~~~~~~~~~~~~~~~~~~~~~~~~~~

Manila has the ability to manage and unmanage shares. If there is a share in
the storage and it is not in OpenStack, you can manage that share and use it
as a manila share. Hitachi NAS Platform File Services Driver for OpenStack use
virtual-volumes (V-VOLs) to create shares. Only V-VOLs with a quota limit
can be used by the driver, also, they must be created or moved inside the
directory '/shares/' and exported (as NFS or CIFS shares). The unmanage
operation only unlinks the share from OpenStack, preserving all data in the
share.

To **manage** shares use:

.. code-block:: console

   $ manila manage [--name <name>] [--description <description>]
   [--share_type <share_type>] [--driver_options [<key=value> [<key=value> ...]]]
   <service_host> <protocol> <export_path>

Where:

+------------------+----------------------------------------------------------+
|  Parameter       | Description                                              |
+==================+==========================================================+
|                  | Manila host, backend and share name. For example         |
|  service_host    | ubuntu\@hitachi1#HITACHI1. The available hosts can be    |
|                  | listed with the command: *manila pool-list* (admin only).|
+------------------+---------------------+------------------------------------+
|  protocol        | NFS or CIFS protocols are currently supported.           |
+------------------+----------------------------------------------------------+
|  export_path     | The export path of the share.                            |
|                  | For example: *172.24.44.31:/shares/some_share_id*        |
+------------------+----------------------------------------------------------+


To **unmanage** a share use:

.. code-block:: console

   $ manila unmanage <share_id>

Where:

+------------------+---------------------------------------------------------+
|  Parameter       | Description                                             |
+==================+=========================================================+
|   share_id       | Manila ID of the share to be unmanaged. This list can   |
|                  | be fetched with: *manila list*.                         |
+------------------+---------------------+-----------------------------------+

Additional Notes
~~~~~~~~~~~~~~~~

- HNAS has some restrictions about the number of EVSs, file systems,
  virtual-volumes and simultaneous SSC connections. Check the manual
  specification for your system.
- Shares and snapshots are thin provisioned. It is reported to manila only the
  real used space in HNAS. Also, a snapshot does not initially take any space in
  HNAS, it only stores the difference between the share and the snapshot, so it
  grows when share data is changed.
- Admins should manage the tenant's quota (*manila quota-update*) to control
  the backend usage.
- By default, CIFS snapshots are disabled when the share is mounted, since it
  uses tree-clone to create snapshots and does not guarantee point-in-time
  replicas when the source directory tree is changing, also, changing
  permissions to *read-only* does not affect already mounted shares. So,
  enable it if your source directory can be static while taking snapshots.
  Currently, it affects only CIFS protocol. For more information check the
  tree-clone feature in HNAS with *man tree-clone*.

The :mod:`manila.share.drivers.hitachi.hnas.driver` Module
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. automodule:: manila.share.drivers.hitachi.hnas.driver
    :noindex:
    :members:
    :undoc-members:
    :show-inheritance:
