The high performance XtremIO All Flash Array (AFA) offers Block Storage services to OpenStack. Using the driver, OpenStack Block Storage hosts can connect to an XtremIO Storage cluster.
This section explains how to configure and connect the block storage nodes to an XtremIO storage cluster.
XtremIO version 4.x is supported.
Edit the cinder.conf file by adding the configuration below under the [DEFAULT] section of the file in case of a single back end or under a separate section in case of multiple back ends (for example [XTREMIO]). The configuration file is usually located under the following path /etc/cinder/cinder.conf.
Configuration option = Default value | Description |
---|---|
[DEFAULT] | |
xtremio_array_busy_retry_count = 5 | (Integer) Number of retries in case array is busy |
xtremio_array_busy_retry_interval = 5 | (Integer) Interval between retries in case array is busy |
xtremio_cluster_name = | (String) XMS cluster id in multi-cluster environment |
xtremio_volumes_per_glance_cache = 100 | (Integer) Number of volumes created from each cached glance image |
For a configuration example, refer to the configuration Configuration example.
Configure the driver name by setting the following parameter in the cinder.conf file:
For iSCSI:
volume_driver = cinder.volume.drivers.emc.xtremio.XtremIOIscsiDriver
For Fibre Channel:
volume_driver = cinder.volume.drivers.emc.xtremio.XtremIOFibreChannelDriver
To retrieve the management IP, use the show-xms CLI command.
Configure the management IP by adding the following parameter:
san_ip = XMS Management IP
In XtremIO version 4.0, a single XMS can manage multiple cluster back ends. In such setups, the administrator is required to specify the cluster name (in addition to the XMS IP). Each cluster must be defined as a separate back end.
To retrieve the cluster name, run the show-clusters CLI command.
Configure the cluster name by adding the following parameter:
xtremio_cluster_name = Cluster-Name
Note
When a single cluster is managed in XtremIO version 4.0, the cluster name is not required.
OpenStack Block Storage requires an XtremIO XMS user with administrative privileges. XtremIO recommends creating a dedicated OpenStack user account that holds an administrative user role.
Refer to the XtremIO User Guide for details on user account management.
Create an XMS account using either the XMS GUI or the add-user-account CLI command.
Configure the user credentials by adding the following parameters:
san_login = XMS username
san_password = XMS username password
Configuring multiple storage back ends enables you to create several back-end storage solutions that serve the same OpenStack Compute resources.
When a volume is created, the scheduler selects the appropriate back end to handle the request, according to the specified volume type.
To support thin provisioning and multipathing in the XtremIO Array, the following parameters from the Nova and Cinder configuration files should be modified as follows:
Thin Provisioning
All XtremIO volumes are thin provisioned. The default value of 20 should be maintained for the max_over_subscription_ratio parameter.
The use_cow_images parameter in the nova.conf file should be set to False as follows:
use_cow_images = False
Multipathing
The use_multipath_for_image_xfer parameter in the cinder.conf file should be set to True as follows:
use_multipath_for_image_xfer = True
Limit the number of copies (XtremIO snapshots) taken from each image cache.
xtremio_volumes_per_glance_cache = 100
The default value is 100. A value of 0 ignores the limit and defers to the array maximum as the effective limit.
To enable SSL certificate validation, modify the following option in the cinder.conf file:
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:
driver_ssl_cert_path = Certificate path
The XtremIO Block Storage driver supports CHAP initiator authentication and discovery.
If CHAP initiator authentication is required, set the CHAP Authentication mode to initiator.
To set the CHAP initiator mode using CLI, run the following XMCLI command:
$ modify-chap chap-authentication-mode=initiator
If CHAP initiator discovery is required, set the CHAP discovery mode to initiator.
To set the CHAP initiator discovery mode using CLI, run the following XMCLI command:
$ modify-chap chap-discovery-mode=initiator
The CHAP initiator modes can also be set via the XMS GUI.
Refer to XtremIO User Guide for details on CHAP configuration via GUI and CLI.
The CHAP initiator authentication and discovery credentials (username and password) are generated automatically by the Block Storage driver. Therefore, there is no need to configure the initial CHAP credentials manually in XMS.
You can update the cinder.conf file by editing the necessary parameters as follows:
[Default]
enabled_backends = XtremIO
[XtremIO]
volume_driver = cinder.volume.drivers.emc.xtremio.XtremIOFibreChannelDriver
san_ip = XMS_IP
xtremio_cluster_name = Cluster01
san_login = XMS_USER
san_password = XMS_PASSWD
volume_backend_name = XtremIOAFA
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