Configure the Storwize family and SVC system

The Storwize family or SVC system must be configured for iSCSI, Fibre Channel, or both.

If using iSCSI, each Storwize family or SVC node should have at least one iSCSI IP address. The IBM Storwize/SVC driver uses an iSCSI IP address associated with the volume's preferred node (if available) to attach the volume to the instance, otherwise it uses the first available iSCSI IP address of the system. The driver obtains the iSCSI IP address directly from the storage system; you do not need to provide these iSCSI IP addresses directly to the driver.

	Note
	If using iSCSI, ensure that the compute nodes have iSCSI network access to the Storwize family or SVC system.

	Note
	OpenStack Nova's Grizzly version supports iSCSI multipath. Once this is configured on the Nova host (outside the scope of this documentation), multipath is enabled.

If using Fibre Channel (FC), each Storwize family or SVC node should have at least one WWPN port configured. If the storwize_svc_multipath_enabled flag is set to True in the Cinder configuration file, the driver uses all available WWPNs to attach the volume to the instance (details about the configuration flags appear in the next section). If the flag is not set, the driver uses the WWPN associated with the volume's preferred node (if available), otherwise it uses the first available WWPN of the system. The driver obtains the WWPNs directly from the storage system; you do not need to provide these WWPNs directly to the driver.

	Note
	If using FC, ensure that the compute nodes have FC connectivity to the Storwize family or SVC system.

If using iSCSI for data access and the storwize_svc_iscsi_chap_enabled is set to True, the driver will associate randomly-generated CHAP secrets with all hosts on the Storwize family system. OpenStack compute nodes use these secrets when creating iSCSI connections.

	Note
	CHAP secrets are added to existing hosts as well as newly-created ones. If the CHAP option is enabled, hosts will not be able to access the storage without the generated secrets.

	Note
	Not all OpenStack Compute drivers support CHAP authentication. Please check compatibility before using.

	Note
	CHAP secrets are passed from OpenStack Block Storage to Compute in clear text. This communication should be secured to ensure that CHAP secrets are not discovered.

Each instance of the IBM Storwize/SVC driver allocates all volumes in a single pool. The pool should be created in advance and be provided to the driver using the storwize_svc_volpool_name configuration flag. Details about the configuration flags and how to provide the flags to the driver appear in the next section.

The driver requires access to the Storwize family or SVC system management interface. The driver communicates with the management using SSH. The driver should be provided with the Storwize family or SVC management IP using the san_ip flag, and the management port should be provided by the san_ssh_port flag. By default, the port value is configured to be port 22 (SSH).

	Note
	Make sure the compute node running the cinder-volume management driver has SSH network access to the storage system.

To allow the driver to communicate with the Storwize family or SVC system, you must provide the driver with a user on the storage system. The driver has two authentication methods: password-based authentication and SSH key pair authentication. The user should have an Administrator role. It is suggested to create a new user for the management driver. Please consult with your storage and security administrator regarding the preferred authentication method and how passwords or SSH keys should be stored in a secure manner.

	Note
	When creating a new user on the Storwize or SVC system, make sure the user belongs to the Administrator group or to another group that has an Administrator role.

If using password authentication, assign a password to the user on the Storwize or SVC system. The driver configuration flags for the user and password are san_login and san_password, respectively.

If you are using the SSH key pair authentication, create SSH private and public keys using the instructions below or by any other method. Associate the public key with the user by uploading the public key: select the "choose file" option in the Storwize family or SVC management GUI under "SSH public key". Alternatively, you may associate the SSH public key using the command line interface; details can be found in the Storwize and SVC documentation. The private key should be provided to the driver using the san_private_key configuration flag.

You can create an SSH key pair using OpenSSH, by running:

$ ssh-keygen -t rsa

The command prompts for a file to save the key pair. For example, if you select 'key' as the filename, two files are created: key and key.pub. The key file holds the private SSH key and key.pub holds the public SSH key.

The command also prompts for a pass phrase, which should be empty.

The private key file should be provided to the driver using the san_private_key configuration flag. The public key should be uploaded to the Storwize family or SVC system using the storage management GUI or command line interface.

	Note
	Ensure that Cinder has read permissions on the private key file.