Coho Data volume driver¶

Supported operations¶

• Create, delete, attach, detach, retype, clone, and extend volumes.
• Create, list, and delete volume snapshots.
• Create a volume from a snapshot.
• Copy a volume to an image.
• Copy an image to a volume.
• Create a thin provisioned volume.
• Get volume statistics.

Coho Data QoS support¶

QoS support for the Coho Data driver includes the ability to set the following capabilities in the OpenStack Block Storage API cinder.api.contrib.qos_specs_manage QoS specs extension module:

• maxIOPS - The maximum number of IOPS allowed for this volume.
• maxMBS - The maximum throughput allowed for this volume.

The QoS keys above must be created and associated with a volume type. For information about how to set the key-value pairs and associate them with a volume type, see the volume qos section in the OpenStackClient command list.

System requirements¶

• NFS client on the Block storage controller.

Coho Data Block Storage driver configuration¶

1. Create cinder volume type.

   $ openstack volume type create coho-1
   

2. 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 Coho Data storage:

   [DEFAULT]
   enabled_backends = coho-1
   default_volume_type = coho-1
   
   [coho-1]
   volume_driver = cinder.volume.drivers.coho.CohoDriver
   volume_backend_name = coho-1
   nfs_shares_config = /etc/cinder/coho_shares
   nas_secure_file_operations = 'false'
   

3. Add your list of Coho Datastream NFS addresses to the file you specified with the nfs_shares_config option. For example, if the value of this option was set to /etc/cinder/coho_shares, then:

   $ cat /etc/cinder/coho_shares
   <coho-nfs-ip>:/<export-path>
   

4. Restart the cinder-volume service to enable Coho Data driver.