Dell PowerStore driver

This section explains how to configure and connect the block storage nodes to an PowerStore storage cluster.

Supported operations

  • Create, delete, attach and detach volumes.

  • Create, delete volume snapshots.

  • Create a volume from a snapshot.

  • Copy an image to a volume.

  • Copy a volume to an image.

  • Clone a volume.

  • Extend a volume.

  • Get volume statistics.

  • Attach a volume to multiple servers simultaneously (multiattach).

  • Revert a volume to a snapshot.

  • OpenStack replication v2.1 support.

  • Create, delete, update Consistency Groups.

  • Create, delete Consistency Groups snapshots.

  • Clone a Consistency Group.

  • Create a Consistency Group from a Consistency Group snapshot.

Driver configuration

Add the following content into /etc/cinder/cinder.conf:

[DEFAULT]
enabled_backends = powerstore

[powerstore]
# PowerStore REST IP
san_ip = <San IP>
# PowerStore REST username and password
san_login = <San username>
san_password = <San Password>
# Storage protocol
storage_protocol = <Storage protocol> # FC or iSCSI
# Volume driver name
volume_driver = cinder.volume.drivers.dell_emc.powerstore.driver.PowerStoreDriver
# Backend name
volume_backend_name = <Backend name>
# PowerStore allowed ports
powerstore_ports = <Allowed ports> # Ex. 58:cc:f0:98:49:22:07:02,58:cc:f0:98:49:23:07:02

Driver options

The driver supports the following configuration options:

Description of configuration options

Configuration option = Default value

Description

powerstore_ports = []

(List of String) Allowed ports. Comma separated list of PowerStore iSCSI IPs or FC WWNs (ex. 58:cc:f0:98:49:22:07:02) to be used. If option is not set all ports are allowed.

powerstore_appliances = []

(List of String) Appliances names. Comma separated list of PowerStore appliances names used to provision volumes. DEPRECATED

SSL support

To enable the SSL certificate verification, modify the following options in the cinder.conf file:

driver_ssl_cert_verify = True
driver_ssl_cert_path = <path to the CA>

By default, the SSL certificate validation is disabled.

If the driver_ssl_cert_path option is omitted, the system default CA will be used.

Thin provisioning and compression

The driver creates thin provisioned compressed volumes by default. Thick provisioning is not supported.

CHAP authentication support

The driver supports one-way (Single mode) CHAP authentication. To use CHAP authentication CHAP Single mode has to be enabled on the storage side.

Note

When enabling CHAP, any previously added hosts will need to be updated with CHAP configuration since there will be I/O disruption for those hosts. It is recommended that before adding hosts to the cluster, decide what type of CHAP configuration is required, if any.

CHAP configuration is retrieved from the storage during driver initialization, no additional configuration is needed. Secrets are generated automatically.

Replication support

Configure replication

  1. Pair source and destination PowerStore systems.

  2. Create Protection policy and Replication rule with desired RPO.

  3. Enable replication in cinder.conf file.

    To enable replication feature for storage backend set replication_device as below:

    ...
    replication_device = backend_id:powerstore_repl_1,
                         san_ip: <Replication system San ip>,
                         san_login: <Replication system San username>,
                         san_password: <Replication system San password>
    
    • Only one replication device is supported for storage backend.

    • Replication device supports the same options as the main storage backend.

  4. Create volume type for volumes with replication enabled.

    $ openstack volume type create powerstore_replicated
    $ openstack volume type set --property replication_enabled='<is> True' powerstore_replicated
    
  5. Set Protection policy name for volume type.

    $ openstack volume type set --property powerstore:protection_policy=<protection policy name> \
        powerstore_replicated
    

Failover host

In the event of a disaster, or where there is a required downtime the administrator can issue the failover host command:

$ cinder failover-host cinder_host@powerstore --backend_id powerstore_repl_1

After issuing Cinder failover-host command Cinder will switch to configured replication device, however to get existing instances to use this target and new paths to volumes it is necessary to first shelve Nova instances and then unshelve them, this will effectively restart the Nova instance and re-establish data paths between Nova instances and the volumes.

$ nova shelve <server>
$ nova unshelve [--availability-zone <availability_zone>] <server>

If the primary system becomes available, the administrator can initiate failback operation using --backend_id default:

$ cinder failover-host cinder_host@powerstore --backend_id default

Consistency Groups support

To use PowerStore Volume Groups create Group Type with consistent group snapshot enabled.

$ cinder --os-volume-api-version 3.11 group-type-create powerstore_vg
$ cinder --os-volume-api-version 3.11 group-type-key powerstore_vg set consistent_group_snapshot_enabled="<is> True"

Note

Currently driver does not support Consistency Groups replication. Adding volume to Consistency Group and creating volume in Consistency Group will fail if volume is replicated.