Generic approach for share provisioning

Generic approach for share provisioning

The Shared File Systems service can be configured to use Compute VMs and Block Storage service volumes. There are two modules that handle them in the Shared File Systems service:

  • The service_instance module creates VMs in Compute with a predefined image called service image. This module can be used by any driver for provisioning of service VMs to be able to separate share resources among tenants.
  • The generic module operates with Block Storage service volumes and VMs created by the service_instance module, then creates shared filesystems based on volumes attached to VMs.

Network configurations

Each driver can handle networking in its own way, see: https://wiki.openstack.org/wiki/manila/Networking.

One of the two possible configurations can be chosen for share provisioning using the service_instance module:

  • Service VM has one network interface from a network that is connected to a public router. For successful creation of a share, the user network should be connected to a public router, too.
  • Service VM has two network interfaces, the first one is connected to the service network, the second one is connected directly to the user’s network.

Requirements for service image

  • Linux based distro
  • NFS server
  • Samba server >= 3.2.0, that can be configured by data stored in registry
  • SSH server
  • Two network interfaces configured to DHCP (see network approaches)
  • exportfs and net conf libraries used for share actions
  • The following files will be used, so if their paths differ one needs to create at least symlinks for them:
    • /etc/exports: permanent file with NFS exports.
    • /var/lib/nfs/etab: temporary file with NFS exports used by exportfs.
    • /etc/fstab: permanent file with mounted filesystems.
    • /etc/mtab: temporary file with mounted filesystems used by mount.

Supported shared filesystems and operations

The driver supports CIFS and NFS shares.

The following operations are supported:

  • Create a share.

  • Delete a share.

  • Allow share access.

    Note the following limitations:

    • Only IP access type is supported for NFS and CIFS.
  • Deny share access.

  • Create a snapshot.

  • Delete a snapshot.

  • Create a share from a snapshot.

  • Extend a share.

  • Shrink a share.

Known restrictions

  • One of nova’s configurations only allows 26 shares per server. This limit comes from the maximum number of virtual PCI interfaces that are used for block device attaching. There are 28 virtual PCI interfaces, in this configuration, two of them are used for server needs and the other 26 are used for attaching block devices that are used for shares.

Using Windows instances

While the generic driver only supports Linux instances, you may use the Windows SMB driver when Windows instances are preferred.

For more details, please check out the following page: Windows SMB driver.

Driver options

The following table contains the configuration options specific to this driver.

Description of Generic share driver configuration options
Configuration option = Default value Description
[DEFAULT]  
connect_share_server_to_tenant_network = False (Boolean) Attach share server directly to share network. Used only with Neutron and if driver_handles_share_servers=True.
container_volume_group = manila_docker_volumes (String) LVM volume group to use for volumes. This volume group must be created by the cloud administrator independently from manila operations.
driver_handles_share_servers = None (Boolean) There are two possible approaches for share drivers in Manila. First is when share driver is able to handle share-servers and second when not. Drivers can support either both or only one of these approaches. So, set this opt to True if share driver is able to handle share servers and it is desired mode else set False. It is set to None by default to make this choice intentional.
goodness_function = None (String) String representation for an equation that will be used to determine the goodness of a host.
interface_driver = manila.network.linux.interface.OVSInterfaceDriver (String) Vif driver. Used only with Neutron and if driver_handles_share_servers=True.
manila_service_keypair_name = manila-service (String) Keypair name that will be created and used for service instances. Only used if driver_handles_share_servers=True.
max_time_to_attach = 120 (Integer) Maximum time to wait for attaching cinder volume.
max_time_to_build_instance = 300 (Integer) Maximum time in seconds to wait for creating service instance.
max_time_to_create_volume = 180 (Integer) Maximum time to wait for creating cinder volume.
max_time_to_extend_volume = 180 (Integer) Maximum time to wait for extending cinder volume.
ovs_integration_bridge = br-int (String) Name of Open vSwitch bridge to use.
path_to_private_key = None (String) Path to host’s private key.
path_to_public_key = ~/.ssh/id_rsa.pub (String) Path to hosts public key. Only used if driver_handles_share_servers=True.
protocol_access_mapping = {'ip': ['nfs'], 'user': ['cifs']} (Dict) Protocol access mapping for this backend. Should be a dictionary comprised of {‘access_type1’: [‘share_proto1’, ‘share_proto2’], ‘access_type2’: [‘share_proto2’, ‘share_proto3’]}.
service_image_name = manila-service-image (String) Name of image in Glance, that will be used for service instance creation. Only used if driver_handles_share_servers=True.
service_instance_flavor_id = 100 (Integer) ID of flavor, that will be used for service instance creation. Only used if driver_handles_share_servers=True.
service_instance_name_or_id = None (String) Name or ID of service instance in Nova to use for share exports. Used only when share servers handling is disabled.
service_instance_name_template = manila_service_instance_%s (String) Name of service instance. Only used if driver_handles_share_servers=True.
service_instance_network_helper_type = neutron (String) DEPRECATED: Used to select between neutron and nova helpers when driver_handles_share_servers=True. Obsolete. This option isn’t used any longer because nova networking is no longer supported.
service_instance_password = None (String) Password for service instance user.
service_instance_security_group = manila-service (String) Security group name, that will be used for service instance creation. Only used if driver_handles_share_servers=True.
service_instance_smb_config_path = $share_mount_path/smb.conf (String) Path to SMB config in service instance.
service_instance_user = None (String) User in service instance that will be used for authentication.
service_net_name_or_ip = None (String) Can be either name of network that is used by service instance within Nova to get IP address or IP address itself for managing shares there. Used only when share servers handling is disabled.
service_network_cidr = 10.254.0.0/16 (String) CIDR of manila service network. Used only with Neutron and if driver_handles_share_servers=True.
service_network_division_mask = 28 (Integer) This mask is used for dividing service network into subnets, IP capacity of subnet with this mask directly defines possible amount of created service VMs per tenant’s subnet. Used only with Neutron and if driver_handles_share_servers=True.
service_network_name = manila_service_network (String) Name of manila service network. Used only with Neutron. Only used if driver_handles_share_servers=True.
share_helpers = CIFS=manila.share.drivers.helpers.CIFSHelperIPAccess, NFS=manila.share.drivers.helpers.NFSHelper (List) Specify list of share export helpers.
share_mount_path = /shares (String) Parent path in service instance where shares will be mounted.
share_mount_template = mount -vt %(proto)s %(options)s %(export)s %(path)s (String) The template for mounting shares for this backend. Must specify the executable with all necessary parameters for the protocol supported. ‘proto’ template element may not be required if included in the command. ‘export’ and ‘path’ template elements are required. It is advisable to separate different commands per backend.
share_unmount_template = umount -v %(path)s (String) The template for unmounting shares for this backend. Must specify the executable with all necessary parameters for the protocol supported. ‘path’ template element is required. It is advisable to separate different commands per backend.
share_volume_fstype = ext4 (String) Filesystem type of the share volume.
tenant_net_name_or_ip = None (String) Can be either name of network that is used by service instance within Nova to get IP address or IP address itself for exporting shares. Used only when share servers handling is disabled.
volume_name_template = manila-share-%s (String) Volume name template.
volume_snapshot_name_template = manila-snapshot-%s (String) Volume snapshot name template.
[cinder]  
auth_section = None (Unknown) Config Section from which to load plugin specific options
auth_type = None (Unknown) Authentication type to load
cafile = None (String) PEM encoded Certificate Authority to use when verifying HTTPs connections.
certfile = None (String) PEM encoded client certificate cert file
cross_az_attach = True (Boolean) Allow attaching between instances and volumes in different availability zones.
endpoint_type = publicURL (String) Endpoint type to be used with cinder client calls.
http_retries = 3 (Integer) Number of cinderclient retries on failed HTTP calls.
insecure = False (Boolean) Verify HTTPS connections.
keyfile = None (String) PEM encoded client certificate key file
region_name = None (String) Region name for connecting to cinder.
timeout = None (Integer) Timeout value for http requests
[neutron]  
cafile = None (String) PEM encoded Certificate Authority to use when verifying HTTPs connections.
certfile = None (String) PEM encoded client certificate cert file
insecure = False (Boolean) Verify HTTPS connections.
keyfile = None (String) PEM encoded client certificate key file
timeout = None (Integer) Timeout value for http requests
[nova]  
api_microversion = 2.10 (String) Version of Nova API to be used.
auth_section = None (Unknown) Config Section from which to load plugin specific options
auth_type = None (Unknown) Authentication type to load
cafile = None (String) PEM encoded Certificate Authority to use when verifying HTTPs connections.
certfile = None (String) PEM encoded client certificate cert file
endpoint_type = publicURL (String) Endpoint type to be used with nova client calls.
insecure = False (Boolean) Verify HTTPS connections.
keyfile = None (String) PEM encoded client certificate key file
region_name = None (String) Region name for connecting to nova.
timeout = None (Integer) Timeout value for http requests
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