Dell EMC VMAX driver¶

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

The VMAX plug-in manages the VMAX to provide shared file systems. The EMC driver framework with the VMAX plug-in is referred to as the VMAX driver in this document.

This driver performs the operations on VMAX eNAS by XMLAPI and the file command line. Each back end manages one Data Mover of VMAX. Multiple Shared File Systems service back ends need to be configured to manage multiple Data Movers.

Requirements¶

VMAX eNAS OE for File version 8.1 or higher
VMAX Unified or File only
The following licenses should be activated on VMAX for File:
- CIFS
- NFS
- SnapSure (for snapshot)
- ReplicationV2 (for create share from snapshot)

Supported shared file systems 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.
- Only user access type is supported for CIFS.
Deny share access.
Create a snapshot.
Delete a snapshot.
Create a share from a snapshot.

While the generic driver creates shared file systems based on cinder volumes attached to nova VMs, the VMAX driver performs similar operations using the Data Movers on the array.

Pre-configurations on VMAX¶

Enable Unicode on Data Mover.

The VMAX driver requires that the Unicode is enabled on Data Mover.

Warning

After enabling Unicode, you cannot disable it. If there are some file systems created before Unicode is enabled on the VMAX, consult the storage administrator before enabling Unicode.

To check the Unicode status on Data Mover, use the following VMAX eNAS File commands on the VMAX control station:
```
server_cifs <MOVER_NAME> | head
# 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, use the following command:
```
uc_config -on -mover <MOVER_NAME>
# MOVER_NAME = <name of the Data Mover>
```
Refer to the document Using International Character Sets on VMAX for File on EMC support site for more information.
Enable CIFS service on Data Mover.

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

To start the CIFS service, use the following command:
```
server_setup <MOVER_NAME> -Protocol cifs -option start [=<n>]
# 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 the following command:
```
server_cifs <MOVER_NAME> | head
# MOVER_NAME = <name of the Data Mover>
```
The command output will show the number of CIFS threads started.
NTP settings on Data Mover.

VMAX 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 a 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.

We recommend setting 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 with the following command:
```
server_date <MOVER_NAME>
# MOVER_NAME = <name of the Data Mover>
```
Set the NTP server for Data Mover with the following command:
```
server_date <MOVER_NAME> timesvc start ntp <host> [<host> ...]
# 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.
Configure User Mapping on the Data Mover.

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

To check usermapper status, use the following command syntax:
```
server_usermapper <movername>
# movername = <name of the Data Mover>
```
If usermapper does not start, use the following command to start the usermapper:
```
server_usermapper <movername> -enable
# movername = <name of the Data Mover>
```
For a multiple protocol environment, refer to Configuring VMAX eNAS User Mapping on EMC support site for additional information.
Configure network connection.

Find the network devices (physical port on NIC) of the Data Mover that has access to the share network.

To check the device list, go to Unisphere > Settings > Network > Device.

Back-end configurations¶

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

emc_share_backend = vmax
emc_nas_server = <IP address>
emc_nas_password = <password>
emc_nas_login = <user>
emc_nas_server_container = <Data Mover name>
emc_nas_pool_names = <Comma separated pool names>
share_driver = manila.share.drivers.emc.driver.EMCShareDriver
emc_interface_ports = <Comma separated ports list>

emc_share_backend

The plug-in name. Set it to vmax for the VMAX driver.
emc_nas_server

The control station IP address of the VMAX system to be managed.
emc_nas_password and emc_nas_login

The fields that are used to provide credentials to the VMAX system. Only local users of VMAX File is supported.
emc_nas_server_container

Name of the Data Mover to serve the share service.
emc_nas_pool_names

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

Examples: pool_1, pool_*, *
emc_interface_ports

Comma-separated list specifying the ports (devices) of Data Mover that can be used for share server interface. Do not set this option if all ports on the Data Mover can be used. Wild card character is supported.

Examples: spa_eth1, spa_*, *

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

Restrictions¶

The VMAX 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, VMAX 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.
The domain name of the active_directory security service should be unique even for different tenants.
The time on the Data Mover and the Active Directory domains used in security services should be in sync (time difference should be less than 10 minutes). We recommended using same NTP server on both the Data Mover and Active Directory domains.
On eNAS, the snapshot is stored in the SavVols. eNAS 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 eNAS. 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. We recommend the administrator configures the notification on the SavVol usage. Refer to Using eNAS SnapSure document on EMC support site for more information.
eNAS has limitations on the overall numbers of Virtual Data Movers, filesystems, shares, and checkpoints. Virtual Data Mover(VDM) is created by the eNAS driver on the eNAS to serve as the Shared File Systems service share server. Similarly, the filesystem is created, mounted, and exported from the VDM over CIFS or NFS protocol to serve as the Shared File Systems service share. The eNAS checkpoint serves as the Shared File Systems service share snapshot. Refer to the NAS Support Matrix document on EMC support site for the limitations and configure the quotas accordingly.

Driver options¶

Configuration options specific to this driver are documented in Description of EMC share driver configuration options.