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](https://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](https://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> emc_interface_ports = <Comma separated ports
list> share_driver =
manila.share.drivers.dell_emc.driver.EMCShareDriver
driver_handles_share_servers = True

• 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.
• emc_interface_ports is comma
  separated list specifying the ports(devices) of Data Mover that can be
  used for share server interface. Members of the list can be Unix-style
  glob expressions (supports Unix shell-style wildcards). This list is
  optional. In the absence of this option, any of the ports on the Data
  Mover can be used.
• driver_handles_share_servers must be
  True, the driver will choose a port from port list which configured in
  emc_interface_ports.

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

IPv6 support

IPv6 support for VNX 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 VNX 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 VNX driver:

network_plugin_ipv6_enabled = True

• network_plugin_ipv6_enabled indicates
  IPv6 is enabled.

If you want to connect VNX using IPv6 address, you should configure
IPv6 address by nas_cs command for VNX
and specify the address in `/etc/manila/manila.conf`:

emc_nas_server = <IPv6 address>

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}

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](https://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](https://support.emc.com) for
  the limitations and configure the quotas accordingly.

The manila.share.drivers.dell_emc.driver Module

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