VNX Driver

EMC manila driver framework (EMCShareDriver) utilizes the EMC storage products to provide the shared filesystems to OpenStack. The EMC manila driver is a plugin based driver which is designed to use different plugins to manage different EMC storage products.

VNX plugin is the plugin which manages the VNX to provide shared filesystems. EMC driver framework with VNX plugin is referred to as VNX driver in this document.

This driver performs the operations on VNX by XMLAPI and the File command line. Each backend manages one Data Mover of VNX. Multiple manila backends need to be configured to manage multiple Data Movers.

Requirements

• VNX OE for File version 7.1 or higher.
• VNX Unified, File only, or Gateway system with single storage backend.
• The following licenses should be activated on VNX for File: * CIFS * NFS * SnapSure (for snapshot) * ReplicationV2 (for create share from snapshot)

Supported Operations

The following operations will be supported on VNX array:

• Create CIFS/NFS Share
• Delete CIFS/NFS Share
• Allow CIFS/NFS Share access * Only IP access type is supported for NFS. * Only user access type is supported for CIFS.
• Deny CIFS/NFS Share access
• Create snapshot
• Delete snapshot
• Create share from snapshot

While the generic driver creates shared filesystems based on Cinder volumes attached to Nova VMs, the VNX driver performs similar operations using the Data Movers on the array.

Pre-Configurations on VNX

1. Enable Unicode on Data mover

VNX driver requires that the Unicode is enabled on Data Mover.

CAUTION: After enabling Unicode, you cannot disable it. If there are some filesystems created before Unicode is enabled on the VNX, consult the storage administrator before enabling Unicode.

To check the Unicode status on Data Mover, use the following VNX File command on VNX control station:

server_cifs <mover_name> | head where: mover_name = <name of the Data Mover>

Check the value of I18N mode field. UNICODE mode is shown as I18N mode = UNICODE

To enable the Unicode for Data Mover:

uc_config -on -mover <mover_name> where: mover_name = <name of the Data Mover>

Refer to the document Using International Character Sets on VNX for File on [EMC support site](http://support.emc.com) for more information.

2. Enable CIFS service on Data Mover

Ensure the CIFS service is enabled on the Data Mover which is going to be managed by VNX driver.

To start the CIFS service, use the following command:

server_setup <mover_name> -Protocol cifs -option start [=<n>] where: <mover_name> = <name of the Data Mover> [=<n>] = <number of threads for CIFS users>

Note: If there is 1 GB of memory on the Data Mover, the default is 96 threads; however, if there is over 1 GB of memory, the default number of threads is 256.

To check the CIFS service status, use this command:

server_cifs <mover_name> | head where: <mover_name> = <name of the Data Mover>

The command output will show the number of CIFS threads started.

3. NTP settings on Data Mover

VNX driver only supports CIFS share creation with share network which has an Active Directory security-service associated.

Creating CIFS share requires that the time on the Data Mover is in sync with the Active Directory domain so that the CIFS server can join the domain. Otherwise, the domain join will fail when creating share with this security service. There is a limitation that the time of the domains used by security-services even for different tenants and different share networks should be in sync. Time difference should be less than 10 minutes.

It is recommended to set the NTP server to the same public NTP server on both the Data Mover and domains used in security services to ensure the time is in sync everywhere.

Check the date and time on Data Mover:

server_date <mover_name> where: mover_name = <name of the Data Mover>

Set the NTP server for Data Mover:

server_date <mover_name> timesvc start ntp <host> [<host> ...] where: mover_name = <name of the Data Mover> host = <IP address of the time server host>

Note: The host must be running the NTP protocol. Only 4 host entries are allowed.

4. Configure User Mapping on the Data Mover

Before creating CIFS share using VNX driver, you must select a method of mapping Windows SIDs to UIDs and GIDs. EMC recommends using usermapper in single protocol (CIFS) environment which is enabled on VNX by default.

To check usermapper status, use this command syntax:

server_usermapper <movername> where: <movername> = <name of the Data Mover>

If usermapper is not started, the following command can be used to start the usermapper:

server_usermapper <movername> -enable where: <movername> = <name of the Data Mover>

For multiple protocol environment, refer to Configuring VNX User Mapping on [EMC support site](http://support.emc.com) for additional information.

5. Network Connection

In the current release, the share created by VNX driver uses the first network device (physical port on NIC) of Data Mover to access the network.

Go to Unisphere to check the device list: Settings -> Network -> Settings for File (Unified system only) -> Device.

Backend Configuration

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

emc_share_backend = vnx emc_nas_server = <IP address> emc_nas_password = <password> emc_nas_login = <user> emc_nas_server_container = <Data Mover name> emc_nas_pool_name = <pool name> share_driver = manila.share.drivers.emc.driver.EMCShareDriver

• emc_share_backend is the plugin name. Set it to vnx for the VNX driver.
• emc_nas_server is the control station IP address of the VNX system to be managed.
• emc_nas_password and emc_nas_login fields are used to provide credentials to the VNX system. Only local users of VNX File is supported.
• emc_nas_server_container field is the name of the Data Mover to serve the share service.
• emc_nas_pool_name is the pool name user wants to create volume from. The pools can be created using Unisphere for VNX.

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

Restrictions

The VNX driver has the following restrictions:

• Only IP access type is supported for NFS.
• Only user access type is supported for CIFS.
• Only FLAT network and VLAN network are supported.
• VLAN network is supported with limitations. The Neutron subnets in different VLANs that are used to create share networks cannot have overlapped address spaces. Otherwise, VNX may have a problem to communicate with the hosts in the VLANs. To create shares for different VLANs with same subnet address, use different Data Movers.
• The ‘Active Directory’ security service is the only supported security service type and it is required to create CIFS shares.
• Only one security service can be configured for each share network.
• Active Directory domain name of the ‘active_directory’ security service should be unique even for different tenants.
• The time on Data Mover and the Active Directory domains used in security services should be in sync (time difference should be less than 10 minutes). It is recommended to use same NTP server on both the Data Mover and Active Directory domains.
• On VNX the snapshot is stored in the SavVols. VNX system allows the space used by SavVol to be created and extended until the sum of the space consumed by all SavVols on the system exceeds the default 20% of the total space available on the system. If the 20% threshold value is reached, an alert will be generated on VNX. Continuing to create snapshot will cause the old snapshot to be inactivated (and the snapshot data to be abandoned). The limit percentage value can be changed manually by storage administrator based on the storage needs. Administrator is recommended to configure the notification on the SavVol usage. Refer to Using VNX SnapSure document on [EMC support site](http://support.emc.com) for more information.
• VNX has limitations on the overall numbers of Virtual Data Movers, filesystems, shares, checkpoints, and etc. Virtual Data Mover(VDM) is created by the VNX driver on the VNX to serve as the manila share server. Similarly, filesystem is created, mounted, and exported from the VDM over CIFS or NFS protocol to serve as the manila share. The VNX checkpoint serves as the manila share snapshot. Refer to the NAS Support Matrix document on [EMC support site](http://support.emc.com) for the limitations and configure the quotas accordingly.

The manila.share.drivers.emc.driver Module

EMC specific NAS storage driver. This driver is a pluggable driver that allows specific EMC NAS devices to be plugged-in as the underlying backend. Use the Manila configuration variable “share_backend_name” to specify, which backend plugins to use.

class EMCShareDriver(*args, **kwargs)

Bases: manila.share.driver.ShareDriver

EMC specific NAS driver. Allows for NFS and CIFS NAS storage usage.

allow_access(context, share, access, share_server=None)

Allow access to the share.

check_for_setup_error()

Check for setup error.

create_share(context, share, share_server=None)

Is called to create share.

create_share_from_snapshot(context, share, snapshot, share_server=None)

Is called to create share from snapshot.

create_snapshot(context, snapshot, share_server=None)

Is called to create snapshot.

delete_share(context, share, share_server=None)

Is called to remove share.

delete_snapshot(context, snapshot, share_server=None)

Is called to remove snapshot.

deny_access(context, share, access, share_server=None)

Deny access to the share.

do_setup(context)

Any initialization the share driver does while starting.

ensure_share(context, share, share_server=None)

Invoked to sure that share is exported.

extend_share(share, new_size, share_server=None)

Is called to extend share.

get_network_allocations_number()

Returns number of network allocations for creating VIFs.

The manila.share.drivers.emc.plugins.vnx.connection Module

VNX backend for the EMC Manila driver.

class VNXStorageConnection(*args, **kwargs)

Bases: manila.share.drivers.emc.plugins.base.StorageConnection

Implements VNX specific functionality for EMC Manila driver.

allow_access(context, share, access, share_server=None)

Allow access to a share.

check_for_setup_error()

Check for setup error.

connect(emc_share_driver, context)

Connect to VNX NAS server.

create_share(context, share, share_server=None)

Create a share and export it based on protocol used.

create_share_from_snapshot(context, share, snapshot, share_server=None)

Create a share from a snapshot - clone a snapshot.

create_snapshot(context, snapshot, share_server=None)

Create snapshot from share.

delete_share(context, share, share_server=None)

Delete a share.

delete_snapshot(context, snapshot, share_server=None)

Delete a snapshot.

deny_access(context, share, access, share_server=None)

Deny access to a share.

ensure_share(context, share, share_server=None)

Ensure that the share is exported.

extend_share(share, new_size, share_server=None)

get_network_allocations_number()

Returns number of network allocations for creating VIFs.

get_pool(share)

Get the pool name of the share.

setup_server(network_info, metadata=None)

Set up and configures share server with given network parameters.

teardown_server(server_details, security_services=None)

Teardown share server.

update_share_stats(stats_dict)

Communicate with EMCNASClient to get the stats.