openstack-manuals/doc/config-reference/source/block-storage/drivers/emc-scaleio-driver.rst

EMC ScaleIO Block Storage driver configuration

ScaleIO is a software-only solution that uses existing servers' local disks and LAN to create a virtual SAN that has all of the benefits of external storage, but at a fraction of the cost and complexity. Using the driver, Block Storage hosts can connect to a ScaleIO Storage cluster.

This section explains how to configure and connect the block storage nodes to a ScaleIO storage cluster.

Support matrix

ScaleIO version	Supported Linux operating systems
1.32	CentOS 6.x, CentOS 7.x, SLES 11 SP3, SLES 12
2.0	CentOS 6.x, CentOS 7.x, SLES 11 SP3, SLES 12, Ubuntu 14.04

Deployment prerequisites

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

Note

Ubuntu users must follow the specific instructions in the ScaleIO deployment guide for Ubuntu environments. See the Deploying on Ubuntu servers section in ScaleIO Deployment Guide. See scale_io_docs.

Official documentation

To find the ScaleIO documentation:

1. Go to the ScaleIO product documentation page.
2. From the left-side panel, select the relevant version (1.32 or 2.0).
3. Search for "ScaleIO Installation Guide 1.32" or "ScaleIO 2.0 Deployment Guide" accordingly.

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

ScaleIO QoS support

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

• maxIOPS
• maxIOPSperGB
• maxBWS
• maxBWSperGB

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, run the following commands:

$ cinder help qos-create

$ cinder help qos-key

$ cinder help qos-associate

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 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.

ScaleIO 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:

provisioning:type = thin\thick

The old specification: sio:provisioning_type is deprecated.

Oversubscription

Configure the oversubscription ratio by adding the following parameter under the seperate section for ScaleIO:

sio_max_over_subscription_ratio = OVER_SUBSCRIPTION_RATIO

Note

The default value for sio_max_over_subscription_ratio is 10.0.

Oversubscription is calculated correctly by the Block Storage service only if the extra specification provisioning:type appears in the volume type regardless to the default provisioning type. Maximum oversubscription value supported for ScaleIO 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 <cg_configuration_example_emc>.

ScaleIO Block Storage driver configuration

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 [ScaleIO]). The configuration file is usually located at /etc/cinder/cinder.conf.

For a configuration example, refer to the example cinder.conf <cg_configuration_example_emc> .

ScaleIO driver name

Configure the driver name by adding the following parameter:

volume_driver = cinder.volume.drivers.emc.scaleio.ScaleIODriver

ScaleIO MDM server IP

The ScaleIO Meta Data Manager monitors and maintains the available resources and permissions.

To retrieve the MDM server IP address, use the drv_cfg --query_mdms command.

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

san_ip = ScaleIO GATEWAY IP

ScaleIO Protection Domain name

ScaleIO allows multiple Protection Domains (groups of SDSs that provide backup for each other).

To retrieve the available Protection Domains, use the command scli --query_all and search for the Protection Domains section.

Configure the Protection Domain for newly created volumes by adding the following parameter:

sio_protection_domain_name = ScaleIO Protection Domain

ScaleIO Storage Pool name

A ScaleIO Storage Pool is a set of physical devices in a Protection Domain.

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

Configure the Storage Pool for newly created volumes by adding the following parameter:

sio_storage_pool_name = ScaleIO Storage Pool

ScaleIO Storage Pools

Multiple Storage Pools and Protection Domains can be listed for use by the virtual machines.

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

ScaleIO user credentials

Block Storage requires a ScaleIO user with administrative privileges. ScaleIO recommends creating a dedicated OpenStack user account that has an administrative user role.

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

Configure the user credentials by adding the following parameters:

san_login = ScaleIO username

san_password = ScaleIO password

Multiple back ends

Configuring multiple storage back ends allows you to create several back-end storage solutions that serve the same Compute resources.

When a volume is created, the scheduler selects the appropriate back end to handle the request, according to the specified volume type.

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.emc.scaleio.ScaleIODriver
volume_backend_name = scaleio
san_ip = GATEWAY_IP
sio_protection_domain_name = Default_domain
sio_storage_pool_name = Default_pool
sio_storage_pools = Domain1:Pool1,Domain2:Pool2
san_login = SIO_USER
san_password = SIO_PASSWD
san_thin_provision = false

Configuration options

The ScaleIO driver supports these configuration options: