=================================================== Pure Storage iSCSI and Fibre Channel volume drivers =================================================== The Pure Storage FlashArray volume drivers for OpenStack Block Storage interact with configured Pure Storage arrays and support various operations. Support for iSCSI storage protocol is available with the PureISCSIDriver Volume Driver class, and Fibre Channel with PureFCDriver. All drivers are compatible with Purity FlashArrays that support the REST API version 1.2, 1.3, 1.4, or 1.5 (Purity 4.0.0 and newer). Limitations and known issues ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If you do not set up the nodes hosting instances to use multipathing, all network connectivity will use a single physical port on the array. In addition to significantly limiting the available bandwidth, this means you do not have the high-availability and non-disruptive upgrade benefits provided by FlashArray. Multipathing must be used to take advantage of these benefits. Supported operations ~~~~~~~~~~~~~~~~~~~~ * Create, delete, attach, detach, retype, clone, and extend volumes. * Create a volume from snapshot. * Create, list, and delete volume snapshots. * Create, list, update, and delete consistency groups. * Create, list, and delete consistency group snapshots. * Manage and unmanage a volume. * Manage and unmanage a snapshot. * Get volume statistics. * Create a thin provisioned volume. * Replicate volumes to remote Pure Storage array(s). Configure OpenStack and Purity ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You need to configure both your Purity array and your OpenStack cluster. .. note:: These instructions assume that the ``cinder-api`` and ``cinder-scheduler`` services are installed and configured in your OpenStack cluster. Configure the OpenStack Block Storage service --------------------------------------------- In these steps, you will edit the ``cinder.conf`` file to configure the OpenStack Block Storage service to enable multipathing and to use the Pure Storage FlashArray as back-end storage. #. Install Pure Storage PyPI module. A requirement for the Pure Storage driver is the installation of the Pure Storage Python SDK version 1.4.0 or later from PyPI. .. code-block:: console $ pip install purestorage #. Retrieve an API token from Purity. The OpenStack Block Storage service configuration requires an API token from Purity. Actions performed by the volume driver use this token for authorization. Also, Purity logs the volume driver's actions as being performed by the user who owns this API token. If you created a Purity user account that is dedicated to managing your OpenStack Block Storage volumes, copy the API token from that user account. Use the appropriate create or list command below to display and copy the Purity API token: * To create a new API token: .. code-block:: console $ pureadmin create --api-token USER The following is an example output: .. code-block:: console $ pureadmin create --api-token pureuser Name API Token Created pureuser 902fdca3-7e3f-d2e4-d6a6-24c2285fe1d9 2014-08-04 14:50:30 * To list an existing API token: .. code-block:: console $ pureadmin list --api-token --expose USER The following is an example output: .. code-block:: console $ pureadmin list --api-token --expose pureuser Name API Token Created pureuser 902fdca3-7e3f-d2e4-d6a6-24c2285fe1d9 2014-08-04 14:50:30 #. Copy the API token retrieved (``902fdca3-7e3f-d2e4-d6a6-24c2285fe1d9`` from the examples above) to use in the next step. #. Edit the OpenStack Block Storage service configuration file. The following sample ``/etc/cinder/cinder.conf`` configuration lists the relevant settings for a typical Block Storage service using a single Pure Storage array: .. code-block:: ini [DEFAULT] enabled_backends = puredriver-1 default_volume_type = puredriver-1 [puredriver-1] volume_backend_name = puredriver-1 volume_driver = PURE_VOLUME_DRIVER san_ip = IP_PURE_MGMT pure_api_token = PURE_API_TOKEN use_multipath_for_image_xfer = True Replace the following variables accordingly: PURE_VOLUME_DRIVER Use either ``cinder.volume.drivers.pure.PureISCSIDriver`` for iSCSI or ``cinder.volume.drivers.pure.PureFCDriver`` for Fibre Channel connectivity. IP_PURE_MGMT The IP address of the Pure Storage array's management interface or a domain name that resolves to that IP address. PURE_API_TOKEN The Purity Authorization token that the volume driver uses to perform volume management on the Pure Storage array. .. note:: The volume driver automatically creates Purity host objects for initiators as needed. If CHAP authentication is enabled via the ``use_chap_auth`` setting, you must ensure there are no manually created host objects with IQN's that will be used by the OpenStack Block Storage service. The driver will only modify credentials on hosts that it manages. .. note:: If using the PureFCDriver it is recommended to use the OpenStack Block Storage Fibre Channel Zone Manager. Volume auto-eradication ~~~~~~~~~~~~~~~~~~~~~~~ To enable auto-eradication of deleted volumes, snapshots, and consistency groups on deletion, modify the following option in the ``cinder.conf`` file: .. code-block:: ini pure_eradicate_on_delete = true By default, auto-eradication is disabled and all deleted volumes, snapshots, and consistency groups are retained on the Pure Storage array in a recoverable state for 24 hours from time of deletion. SSL certification ~~~~~~~~~~~~~~~~~ To enable SSL certificate validation, modify the following option in the ``cinder.conf`` file: .. code-block:: ini driver_ssl_cert_verify = true By default, SSL certificate validation is disabled. To specify a non-default path to ``CA_Bundle`` file or directory with certificates of trusted CAs: .. code-block:: ini driver_ssl_cert_path = Certificate path .. note:: This requires the use of Pure Storage Python SDK > 1.4.0. Replication configuration ~~~~~~~~~~~~~~~~~~~~~~~~~ Add the following to the back-end specification to specify another Flash Array to replicate to: .. code-block:: ini [puredriver-1] replication_device = backend_id:PURE2_NAME,san_ip:IP_PURE2_MGMT,api_token:PURE2_API_TOKEN Where ``PURE2_NAME`` is the name of the remote Pure Storage system, ``IP_PURE2_MGMT`` is the management IP address of the remote array, and ``PURE2_API_TOKEN`` is the Purity Authorization token of the remote array. Note that more than one ``replication_device`` line can be added to allow for multi-target device replication. A volume is only replicated if the volume is of a volume-type that has the extra spec ``replication_enabled`` set to `` True``. To create a volume type that specifies replication to remote back ends: .. code-block:: console $ openstack volume type create ReplicationType $ openstack volume type set --property replication_enabled=' True' ReplicationType The following table contains the optional configuration parameters available for replication configuration with the Pure Storage array. ==================================================== ============= ====== Option Description Default ==================================================== ============= ====== ``pure_replica_interval_default`` Snapshot replication interval in seconds. ``3600`` ``pure_replica_retention_short_term_default`` Retain all snapshots on target for this time (in seconds). ``14400`` ``pure_replica_retention_long_term_per_day_default`` Retain how many snapshots for each day. ``3`` ``pure_replica_retention_long_term_default`` Retain snapshots per day on target for this time (in days). ``7`` ==================================================== ============= ====== .. note:: ``replication-failover`` is only supported from the primary array to any of the multiple secondary arrays, but subsequent ``replication-failover`` is only supported back to the original primary array. Automatic thin-provisioning/oversubscription ratio ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To enable this feature where we calculate the array oversubscription ratio as (total provisioned/actual used), add the following option in the ``cinder.conf`` file: .. code-block:: ini [puredriver-1] pure_automatic_max_oversubscription_ratio = True By default, this is disabled and we honor the hard-coded configuration option ``max_over_subscription_ratio``. .. note:: Arrays with very good data reduction rates (compression/data deduplication/thin provisioning) can get *very* large oversubscription rates applied. Scheduling metrics ~~~~~~~~~~~~~~~~~~ A large number of metrics are reported by the volume driver which can be useful in implementing more control over volume placement in multi-backend environments using the driver filter and weighter methods. Metrics reported include, but are not limited to: .. code-block:: text total_capacity_gb free_capacity_gb provisioned_capacity total_volumes total_snapshots total_hosts total_pgroups writes_per_sec reads_per_sec input_per_sec output_per_sec usec_per_read_op usec_per_read_op queue_depth .. note:: All total metrics include non-OpenStack managed objects on the array. In conjunction with QOS extra-specs, you can create very complex algorithms to manage volume placement. More detailed documentation on this is available in other external documentation. Configuration Options ~~~~~~~~~~~~~~~~~~~~~ The following list all Pure driver specific configuration options that can be set in `cinder.conf`: .. config-table:: :config-target: Pure cinder.volume.drivers.pure