Dell EMC VxFlex OS (ScaleIO) Storage driver¶

Official VxFlex OS documentation¶

To find the VxFlex OS documentation:

1. Go to the VxFlex OS product documentation page.
2. From the left-side panel, select the relevant VxFlex OS version.

Supported VxFlex OS and ScaleIO Versions¶

The Dell EMC VxFlex OS Block Storage driver has been tested against the following versions of ScaleIO and VxFlex OS and found to be compatible:

• ScaleIO 2.0.x
• ScaleIO 2.5.x
• VxFlex OS 2.6.x

Please consult the Official VxFlex OS documentation to determine supported operating systems for each version of VxFlex OS or ScaleIO.

Deployment prerequisites¶

• The VxFlex OS Gateway must be installed and accessible in the network. For installation steps, refer to the Preparing the installation Manager and the Gateway section in VxFlex OS Deployment Guide. See Official VxFlex OS documentation.
• VxFlex OS Storage Data Client (SDC) must be installed on all OpenStack nodes.

Supported operations¶

• Create, delete, clone, attach, detach, manage, and unmanage volumes
• Create, delete, manage, and unmanage volume snapshots
• Create a volume from a snapshot
• Copy an image to a volume
• Copy a volume to an image
• Extend a volume
• Get volume statistics
• Create, list, update, and delete consistency groups
• Create, list, update, and delete consistency group snapshots

VxFlex OS driver name¶

Configure the driver name by adding the following parameter:

volume_driver = cinder.volume.drivers.dell_emc.scaleio.driver.ScaleIODriver

VxFlex OS Gateway server IP¶

The VxFlex OS Gateway provides a REST interface to VxFlex OS.

Configure the Gateway server IP address by adding the following parameter:

san_ip = <VxFlex OS GATEWAY IP>

VxFlex OS Storage Pools¶

Multiple Storage Pools and Protection Domains can be listed for use by the virtual machines. The list should include every Protection Domain and Storage Pool pair that you would like Cinder to utilize.

To retrieve the available Storage Pools, use the command scli --query_all and search for available Storage Pools.

Configure the available Storage Pools by adding the following parameter:

sio_storage_pools = <Comma-separated list of protection domain:storage pool name>

VxFlex OS user credentials¶

Block Storage requires a VxFlex OS user with administrative privileges. Dell EMC recommends creating a dedicated OpenStack user account that has an administrative user role.

Refer to the VxFlex OS User Guide for details on user account management.

Configure the user credentials by adding the following parameters:

san_login = <SIO_USER>
san_password = <SIO_PASSWD>

Oversubscription¶

Configure the oversubscription ratio by adding the following parameter under the separate section for VxFlex OS:

sio_max_over_subscription_ratio = <OVER_SUBSCRIPTION_RATIO>

Oversubscription is calculated correctly by the Block Storage service only if the extra specification provisioning:type appears in the volume type regardless of the default provisioning type. Maximum oversubscription value supported for VxFlex OS is 10.0.

Default provisioning type¶

If provisioning type settings are not specified in the volume type, the default value is set according to the san_thin_provision option in the configuration file. The default provisioning type will be thin if the option is not specified in the configuration file. To set the default provisioning type thick, set the san_thin_provision option to false in the configuration file, as follows:

san_thin_provision = false

The configuration file is usually located in /etc/cinder/cinder.conf. For a configuration example, see: cinder.conf.

Configuration example¶

cinder.conf example file

You can update the cinder.conf file by editing the necessary parameters as follows:

[DEFAULT]
enabled_backends = scaleio

[scaleio]
volume_driver = cinder.volume.drivers.dell_emc.scaleio.driver.ScaleIODriver
volume_backend_name = scaleio
san_ip = GATEWAY_IP
sio_storage_pools = Domain1:Pool1,Domain2:Pool2
san_login = SIO_USER
san_password = SIO_PASSWD
san_thin_provision = false

Connector configuration¶

Before using attach/detach volume operations VxFlex OS connector must be properly configured. On each node where VxFlex OS SDC is installed do the following:

1. Create /opt/emc/scaleio/openstack/connector.conf if it does not exist.

   $ mkdir -p /opt/emc/scaleio/openstack
   $ touch /opt/emc/scaleio/openstack/connector.conf
   

2. For each VxFlex OS section in the cinder.conf create the same section in the /opt/emc/scaleio/openstack/connector.conf and populate it with passwords. Example:

   [vxflexos]
   san_password = SIO_PASSWD
   
   [vxflexos-new]
   san_password = SIO2_PASSWD
   

Configuration options¶

The VxFlex OS driver supports these configuration options:

VxFlex OS Protection Domain and Storage Pool¶

When multiple storage pools are specified in the Cinder configuration, users can specify which pool should be utilized by adding the pool_name Extra Spec to the volume type extra-specs and setting the value to the requested protection_domain:storage_pool.

$ openstack volume type create sio_type_1
$ openstack volume type set --property volume_backend_name=scaleio sio_type_1
$ openstack volume type set --property pool_name=Domain2:Pool2 sio_type_1

VxFlex OS thin provisioning support¶

The Block Storage driver supports creation of thin-provisioned and thick-provisioned volumes. The provisioning type settings can be added as an extra specification of the volume type, as follows:

$ openstack volume type create sio_type_thick
$ openstack volume type set --property provisioning:type=thick sio_type_thick

VxFlex OS QoS support¶

QoS support for the VxFlex OS driver includes the ability to set the following capabilities:

maxIOPS

The QoS I/O rate limit. If not set, the I/O rate will be unlimited. The setting must be larger than 10.

maxIOPSperGB

The QoS I/O rate limit. The limit will be calculated by the specified value multiplied by the volume size. The setting must be larger than 10.

maxBWS

The QoS I/O bandwidth rate limit in KBs. If not set, the I/O bandwidth rate will be unlimited. The setting must be a multiple of 1024.

maxBWSperGB

The QoS I/O bandwidth rate limit in KBs. The limit will be calculated by the specified value multiplied by the volume size. The setting must be a multiple of 1024.

The QoS keys above must be created and associated with a volume type. For example:

$ openstack volume qos create qos-limit-iops --consumer back-end --property maxIOPS=5000
$ openstack volume type create sio_limit_iops
$ openstack volume qos associate qos-limit-iops sio_limit_iops

The driver always chooses the minimum between the QoS keys value and the relevant calculated value of maxIOPSperGB or maxBWSperGB.

Since the limits are per SDC, they will be applied after the volume is attached to an instance, and thus to a compute node/SDC.