Dell EMC Unity driver

The EMC Shared File Systems service driver framework (EMCShareDriver) utilizes the EMC storage products to provide the shared file systems to OpenStack. The EMC driver is a plug-in based driver which is designed to use different plug-ins to manage different EMC storage products.

The Unity plug-in manages the Unity system to provide shared filesystems. The EMC driver framework with the Unity plug-in is referred to as the Unity driver in this document.

This driver performs the operations on Unity through RESTful APIs. Each backend manages one Storage Processor of Unity. Configure multiple Shared File Systems service backends to manage multiple Unity systems.

Requirements

• Unity OE 4.1.x or higher.

• StorOps 1.1.0 or higher is installed on Manila node.

• Following licenses are activated on Unity:

  • CIFS/SMB Support

  • Network File System (NFS)

  • Thin Provisioning

  • Fiber Channel (FC)

  • Internet Small Computer System Interface (iSCSI)

Supported shared filesystems and operations

In detail, users are allowed to do following operation with EMC Unity Storage Systems.

• Create/delete a NFS share.

• Create/delete a CIFS share.

• Extend the size of a share.

• Shrink the size of a share.

• Modify the host access privilege of a NFS share.

• Modify the user access privilege of a CIFS share.

• Create/Delete snapshot of a share.

• Create a new share from snapshot.

• Revert a share to a snapshot.

• Manage/Unmanage a share server.

• Manage/Unmanage a share.

• Manage/Unmanage a snapshot.

Supported Network Topologies

• Flat

  This type is fully supported by Unity share driver, however flat networks are restricted due to the limited number of tenant networks that can be created from them.

• VLAN

  We recommend this type of network topology in Manila. In most use cases, VLAN is used to isolate the different tenants and provide an isolated network for each tenant. To support this function, an administrator needs to set a slot connected with Unity Ethernet port in Trunk mode or allow multiple VLANs from the slot.

• VXLAN

  Unity native VXLAN is still unavailable. However, with the HPB (Hierarchical Port Binding) in Networking and Shared file system services, it is possible that Unity co-exists with VXLAN enabled network environment.

Pre-Configurations

On Manila Node

Python library storops is required to run Unity driver. Install it with the pip command. You may need root privilege to install python libraries.

$ pip install storops

On Unity System

1. Configure system level NTP server.

   Open Unisphere of your Unity system and navigate to:

   Unisphere -> Settings -> Management -> System Time and NTP
   

   Select Enable NTP synchronization and add your NTP server(s).

   The time on the Unity system and the Active Directory domains used in security services should be in sync. We recommend using the same NTP server on both the Unity system and Active Directory domains.

2. Configure system level DNS server.

   Open Unisphere of your Unity system and navigate to:

   Unisphere -> Settings -> Management -> DNS Server
   

   Select Configure DNS server address manually and add your DNS server(s).

Backend configurations

Following configurations need to be configured in /etc/manila/manila.conf for the Unity driver.

share_driver = manila.share.drivers.dell_emc.driver.EMCShareDriver
emc_share_backend = unity
emc_nas_server = <management IP address of the Unity system>
emc_nas_login = <user with administrator privilege>
emc_nas_password = <password>
unity_server_meta_pool = <pool name>
unity_share_data_pools = <comma separated pool names>
unity_ethernet_ports = <comma separated ports list>
driver_handles_share_servers = True/False
unity_share_server = <name of NAS server in Unity system>
report_default_filter_function = True/False

• emc_share_backend

  The plugin name. Set it to unity for the Unity driver.

• emc_nas_server

  The management IP for Unity.

• unity_server_meta_pool

  The name of the pool to persist the meta-data of NAS server. This option is required.

• unity_share_data_pools

  Comma separated list specifying the name of the pools to be used by this backend. Do not set this option if all storage pools on the system can be used. Wild card character is supported.

  Examples:

  # Only use pool_1
  unity_share_data_pools = pool_1
  # Only use pools whose name stars from pool_
  unity_share_data_pools = pool_*
  # Use all pools on Unity
  unity_share_data_pools = *
  

• unity_ethernet_ports

  Comma separated list specifying the ethernet ports of Unity system that can be used for share. Do not set this option if all ethernet ports can be used. Wild card character is supported. Both the normal ethernet port and link aggregation port can be used by Unity share driver.

  Examples:

  # Only use spa_eth1
  unity_ethernet_ports = spa_eth1
  # Use port whose name stars from spa_
  unity_ethernet_ports = spa_*
  # Use all Link Aggregation ports
  unity_ethernet_ports = sp*_la_*
  # Use all available ports
  unity_ethernet_ports = *
  

• driver_handles_share_servers

  Unity driver requires this option to be as True or False. Need to set unity_share_server when the value is False.

• unity_share_server

  One of NAS server names in Unity, it is used for share creation when the driver is in DHSS=False mode.

• report_default_filter_function

  Whether or not report default filter function. Default value is False. However, this value will be changed to True in a future release to ensure compliance with design expectations in Manila. So we recommend always setting this option in your deployment to True or False per your desired behavior.

Restart of manila-share service is needed for the configuration changes to take effect.

Supported MTU size

Unity currently only supports 1500 and 9000 as the mtu size, the user can change the above mtu size from Unity Unisphere:

1. In the Unisphere, go to Settings, Access, and then Ethernet.

2. Double click the ethernet port.

3. Select the MTU size from the drop down list.

The Unity driver will select the port where mtu is equal to the mtu of share network during share server creation.

IPv6 support

IPv6 support for Unity driver is introduced in Queens release. The feature is divided into two parts:

1. The driver is able to manage share or snapshot in the Neutron IPv6 network.

2. The driver is able to connect Unity management interface using its IPv6 address.

Pre-Configurations for IPv6 support

The following parameters need to be configured in /etc/manila/manila.conf for the Unity driver:

network_plugin_ipv6_enabled = True

• network_plugin_ipv6_enabled indicates IPv6 is enabled.

If you want to connect Unity using IPv6 address, you should configure IPv6 address by /net/if/mgmt uemcli command, mgmtInterfaceSettings RESTful api or the system settings of Unity GUI for Unity and specify the address in /etc/manila/manila.conf:

emc_nas_server = <IPv6 address>

Supported share creation in mode that driver does not create and destroy share servers (DHSS=False)

To create a file share in this mode, you need to:

1. Create NAS server with network interface in Unity system.

2. Set ‘driver_handles_share_servers=False’ and ‘unity_share_server’ in /etc/manila/manila.conf:

   driver_handles_share_servers = False
   unity_share_server = <name of NAS server in Unity system>
   

3. Specify the share type with driver_handles_share_servers = False extra specification:

   $ manila type-create ${share_type_name} False
   

4. Create share.

   $ manila create ${share_protocol} ${size} --name ${share_name} --share-type ${share_type_name}
   

Note

Do not specify the share network in share creation command because no share servers will be created. Driver will use the unity_share_server specified for share creation.

Snapshot support

In the Mitaka and Newton release of OpenStack, Snapshot support is enabled by default for a newly created share type. Starting with the Ocata release, the snapshot_support extra spec must be set to True in order to allow snapshots for a share type. If the ‘snapshot_support’ extra_spec is omitted or if it is set to False, users would not be able to create snapshots on shares of this share type. The feature is divided into two parts:

1. The driver is able to create/delete snapshot of share.

2. The driver is able to create share from snapshot.

Pre-Configurations for Snapshot support

The following extra specifications need to be configured with share type.

• snapshot_support = True

• create_share_from_snapshot_support = True

For new share type, these extra specifications can be set directly when creating share type:

$ manila type-create --snapshot_support True --create_share_from_snapshot_support True ${share_type_name} True

Or you can update already existing share type with command:

$ manila type-key ${share_type_name} set snapshot_support=True
$ manila type-key ${share_type_name} set create_share_from_snapshot_support=True

To snapshot a share and create share from the snapshot

Firstly, you need create a share from share type that has extra specifications (snapshot_support=True, create_share_from_snapshot_support=True). Then snapshot the share with command:

$ manila snapshot-create ${source_share_name} --name ${target_snapshot_name} --description " "

After creating the snapshot from previous step, you can create share from that snapshot. Use command:

$ manila create nfs 1 --name ${target_share_name} --metadata source=snapshot --description " " --snapshot-id ${source_snapshot_id}

To manage an existing share server

To manage a share server existing in Unity System, you need to:

1. Create network, subnet, port (ip address of nas server in Unity system) and share network in OpenStack.

   $ openstack network create ${network_name} --provider-network-type ${network_type}
   $ openstack subnet create ${subnet_name} --network ${network_name} --subnet-range ${subnet_range}
   $ openstack port create --network ${network_name} --fixed-ip subnet=${subnet_name},ip-address=${ip address} \
     ${port_name} --device-owner=manila:share
   $ manila share-network-create --name ${share_network_name} --neutron-net-id ${network_name} \
     --neutron-subnet-id ${subnet_name}
   

2. Manage the share server in OpenStack:

   $ manila share-server-manage ${host} ${share_network_name} ${identifier}
   

   Note

   ‘${identifier}’ is the nas server name in Unity system.

To un-manage a Manila share server

To unmanage a share server existing in OpenStack:

$ manila share-server-unmanage ${share_server_id}

To manage an existing share

To manage a share existing in Unity System:

• In DHSS=True mode

  Need make sure the related share server is existing in OpenStack, otherwise need to manage share server first (check the step of ‘Supported Manage share server’).

  $ manila manage ${service_host} ${protocol} '${export_path}' --name ${share_name} --driver_options size=${share_size} \
    --share_type ${share_type} --share_server_id ${share_server_id}
  

  Note

  ‘${share_server_id}’ is the id of share server in OpenStack. ‘${share_type}’ should have the property ‘driver_handles_share_servers=True’.

• In DHSS=False mode

  $ manila manage ${service_host} ${protocol} '${export_path}' --name ${share_name} --driver_options size=${share_size} \
    --share_type ${share_type}
  

  Note

  ‘${share_type}’ should have the property ‘driver_handles_share_servers=False’.

To un-manage a Manila share

To unmanage a share existing in OpenStack:

$ manila unmanage ${share_id}

To manage an existing share snapshot

To manage a snapshot existing in Unity System, you need make sure the related share instance is existing in OpenStack, otherwise need to manage share first (check the step of ‘Supported Manage share’).

$ manila snapshot-manage --name ${name} ${share_name} ${provider_location} --driver_options size=${snapshot_size}

Note

‘${provider_location}’ is the snapshot name in Unity system. ‘${share_name}’ is the share name or id in OpenStack.

To un-manage a Manila share snapshot

To unmanage a snapshot existing in OpenStack:

$ manila snapshot-unmanage ${snapshot_id}

Supported security services

Unity share driver provides IP based authentication method support for NFS shares and user based authentication method for CIFS shares respectively. For CIFS share, Microsoft Active Directory is the only supported security service.

IO Load balance

The Unity driver automatically distributes the file interfaces per storage processor based on the option unity_ethernet_ports. This balances IO traffic. The recommended configuration for unity_ethernet_ports specifies balanced ports per storage processor. For example:

# Use eth2 from both SPs
unity_ethernet_ports = spa_eth2, spb_eth2

Default filter function

Unity does not support the file system creation with size smaller than 3GB, if the size of share user create is smaller than 3GB, Unity driver will supplement the size to 3GB in Unity.

Unity driver implemented the get_default_filter_function API to report the default filter function, if the share size is smaller than 3GB, Manila will not schedule the share creation to Unity backend.

Unity driver provides an option report_default_filter_function to disable or enable the filter function reporting, the default value is disabled.

Restrictions

The Unity driver has following restrictions.

• EMC Unity does not support the same IP in different VLANs.

• Only IP access type is supported for NFS.

• Only user access type is supported for CIFS.

API Implementations

Following driver features are implemented in the plugin.

• create_share: Create a share and export it based on the protocol used (NFS or CIFS).

• create_share_from_snapshot: Create a share from a snapshot - clone a snapshot.

• delete_share: Delete a share.

• extend_share: Extend the maximum size of a share.

• shrink_share: Shrink the minimum size of a share.

• create_snapshot: Create a snapshot for the specified share.

• delete_snapshot: Delete the snapshot of the share.

• update_access: recover, add or delete user/host access to a share.

• allow_access: Allow access (read write/read only) of a user to a CIFS share. Allow access (read write/read only) of a host to a NFS share.

• deny_access: Remove access (read write/read only) of a user from a CIFS share. Remove access (read write/read only) of a host from a NFS share.

• ensure_share: Check whether share exists or not.

• update_share_stats: Retrieve share related statistics from Unity.

• get_network_allocations_number: Returns number of network allocations for creating VIFs.

• setup_server: Set up and configures share server with given network parameters.

• teardown_server: Tear down the share server.

• revert_to_snapshot: Revert a share to a snapshot.

• get_default_filter_function: Report a default filter function.

Driver options

Configuration options specific to this driver:

Description of Dell EMC Unity share driver configuration options

Configuration option = Default value	Description
[DEFAULT]
unity_ethernet_ports = None	(List) Comma separated list of ports that can be used for share server interfaces. Members of the list can be Unix-style glob expressions.
unity_server_meta_pool = None	(String) Pool to persist the meta-data of NAS server.
unity_share_data_pools = None	(List) Comma separated list of pools that can be used to persist share data.
unity_share_server = None	One of NAS server names in Unity, it is used for share creation when the driver is in DHSS=False mode..