Dell EMC VMAX iSCSI and FC drivers

Contents

Dell EMC VMAX iSCSI and FC drivers

The Dell EMC VMAX drivers, VMAXISCSIDriver and VMAXFCDriver, support the use of Dell EMC VMAX storage arrays with Block Storage. They both provide equivalent functions and differ only in support for their respective host attachment methods.

The drivers perform volume operations by communicating with the back-end VMAX storage. It uses a CIM client in Python called PyWBEM to perform CIM operations over HTTP.

The EMC CIM Object Manager (ECOM) is packaged with the EMC SMI-S provider. It is a CIM server that enables CIM clients to perform CIM operations over HTTP by using SMI-S in the back end for VMAX storage operations.

The Dell EMC SMI-S Provider supports the SNIA Storage Management Initiative (SMI), an ANSI standard for storage management. It supports the VMAX storage system.

System requirements

The Cinder driver supports the VMAX-3 series.

For VMAX-3 series, Solutions Enabler 8.3.0.11 or later is required. This is SSL only. Refer to section below SSL support.

When installing Solutions Enabler, make sure you explicitly add the SMI-S component.

You can download Solutions Enabler from the Dell EMC’s support web site (login is required). See the Solutions Enabler 8.3.0 Installation and Configuration Guide at support.emc.com.

Ensure that there is only one SMI-S (ECOM) server active on the same VMAX array.

Required VMAX software suites for OpenStack

There are five Software Suites available for the VMAX All Flash and Hybrid:

  • Base Suite
  • Advanced Suite
  • Local Replication Suite
  • Remote Replication Suite
  • Total Productivity Pack

OpenStack requires the Advanced Suite and the Local Replication Suite or the Total Productivity Pack (it includes the Advanced Suite and the Local Replication Suite) for the VMAX All Flash and Hybrid.

Each are licensed separately. For further details on how to get the relevant license(s), reference eLicensing Support below.

eLicensing support

To activate your entitlements and obtain your VMAX license files, visit the Service Center on https://support.emc.com, as directed on your License Authorization Code (LAC) letter emailed to you.

  • For help with missing or incorrect entitlements after activation (that is, expected functionality remains unavailable because it is not licensed), contact your EMC account representative or authorized reseller.

  • For help with any errors applying license files through Solutions Enabler, contact the Dell EMC Customer Support Center.

  • If you are missing a LAC letter or require further instructions on activating your licenses through the Online Support site, contact EMC’s worldwide Licensing team at licensing@emc.com or call:

    North America, Latin America, APJK, Australia, New Zealand: SVC4EMC (800-782-4362) and follow the voice prompts.

    EMEA: +353 (0) 21 4879862 and follow the voice prompts.

Supported operations

VMAX drivers support these operations:

  • Create, list, delete, attach, and detach volumes
  • Create, list, and delete volume snapshots
  • Copy an image to a volume
  • Copy a volume to an image
  • Clone a volume
  • Extend a volume
  • Retype a volume (Host and storage assisted volume migration)
  • Create a volume from a snapshot
  • Create and delete consistency group
  • Create and delete consistency group snapshot
  • Modify consistency group (add and remove volumes)
  • Create consistency group from source

VMAX drivers also support the following features:

  • Dynamic masking view creation
  • Dynamic determination of the target iSCSI IP address
  • iSCSI multipath support
  • Oversubscription
  • Live Migration
  • Attach and detach snapshots
  • Volume replication

VMAX All Flash and Hybrid:

  • Service Level support
  • SnapVX support
  • All Flash support
  • Compression support

Note

VMAX All Flash array with Solutions Enabler 8.3.0.11 or later have compression enabled by default when associated with Diamond Service Level. This means volumes added to any newly created storage groups will be compressed.

Setup VMAX drivers

Pywbem Versions
Pywbem Version Ubuntu14.04(LTS),Ubuntu16.04(LTS), Red Hat Enterprise Linux, CentOS and Fedora
  Python2 Python3
pip Native pip Native
0.9.0 No N/A Yes N/A
0.8.4 No N/A Yes N/A
0.7.0 No Yes No Yes

Note

On Python2, use the updated distro version, for example:

# apt-get install python-pywbem

Note

On Python3, use the official pywbem version (V0.9.0 or v0.8.4).

  1. Install the python-pywbem package for your distribution.

    • On Ubuntu:

      # apt-get install python-pywbem
      
    • On openSUSE:

      # zypper install python-pywbem
      
    • On Red Hat Enterprise Linux, CentOS, and Fedora:

      # yum install pywbem
      

    Note

    A potential issue can exist with the python-pywbem dependency package, especially M2crypto. To troubleshot and resolve these types of issues, follow these steps.

    • On Ubuntu:

      # apt-get remove --purge -y python-m2crypto
      # pip uninstall pywbem
      # apt-get install python-pywbem
      
    • On openSUSE:

      # zypper remove --clean-deps python-m2crypto
      # pip uninstall pywbem
      # zypper install python-pywbem
      
    • On Red Hat Enterprise Linux, CentOS, and Fedora:

      # yum remove python-m2crypto
      # sudo pip uninstall pywbem
      # yum install pywbem
      
  2. Install iSCSI Utilities (for iSCSI drivers only).

    1. Download and configure the Cinder node as an iSCSI initiator.

    2. Install the open-iscsi package.

      • On Ubuntu:

        # apt-get install open-iscsi
        
      • On openSUSE:

        # zypper install open-iscsi
        
      • On Red Hat Enterprise Linux, CentOS, and Fedora:

        # yum install scsi-target-utils.x86_64
        
  3. Download Solutions Enabler from support.emc.com and install it. Make sure you install the SMIS component. A [Y]es response installs the SMISPROVIDER component.

    Install EMC Solutions Enabler SMIS Component ? [N]:Y
    

    You can install Solutions Enabler on a non-OpenStack host. Supported platforms include different flavors of Windows, Red Hat, and SUSE Linux. Solutions Enabler can be installed on a physical server or a VM hosted by an ESX server. Note that the supported hypervisor for a VM running Solutions Enabler is ESX only. See the Solutions Enabler 8.3.0 Installation and Configuration Guide on support.emc.com for more details.

    Note

    You must discover storage arrays on the ECOM before you can use the VMAX drivers. Follow instructions in Solutions Enabler 8.3.0 Installation and Configuration Guide on support.emc.com for more details.

    The ECOM server is usually installed at /opt/emc/ECIM/ECOM/bin on Linux and C:\Program Files\EMC\ECIM\ECOM\bin on Windows. After you install and configure the ECOM, go to that directory and type TestSmiProvider.exe for windows and ./TestSmiProvider for linux

    Use disco in TestSmiProvider to add an array. Use dv and examine the output after the array is added. In advance of TestSmiProvider, arrays need to be discovered on the Solutions Enabler by using the symcfg discover command. Make sure that the arrays are recognized by the SMI-S server before using the EMC VMAX drivers.

  4. Configure Block Storage

    Add the following entries to /etc/cinder/cinder.conf:

    enabled_backends = CONF_GROUP_ISCSI, CONF_GROUP_FC
    
    [CONF_GROUP_ISCSI]
    volume_driver = cinder.volume.drivers.dell_emc.vmax.iscsi.VMAXISCSIDriver
    cinder_emc_config_file = /etc/cinder/cinder_emc_config_CONF_GROUP_ISCSI.xml
    volume_backend_name = ISCSI_backend
    
    [CONF_GROUP_FC]
    volume_driver = cinder.volume.drivers.dell_emc.vmax.fc.VMAXFCDriver
    cinder_emc_config_file = /etc/cinder/cinder_emc_config_CONF_GROUP_FC.xml
    volume_backend_name = FC_backend
    

    In this example, two back-end configuration groups are enabled: CONF_GROUP_ISCSI and CONF_GROUP_FC. Each configuration group has a section describing unique parameters for connections, drivers, the volume_backend_name, and the name of the EMC-specific configuration file containing additional settings. Note that the file name is in the format /etc/cinder/cinder_emc_config_[confGroup].xml.

    Once the cinder.conf and EMC-specific configuration files have been created, openstack commands need to be issued in order to create and associate OpenStack volume types with the declared volume_backend_names:

    $ openstack volume type create VMAX_ISCSI
    $ openstack volume type set --property volume_backend_name=ISCSI_backend VMAX_ISCSI
    $ openstack volume type create VMAX_FC
    $ openstack volume type set --property volume_backend_name=FC_backend VMAX_FC
    

    By issuing these commands, the Block Storage volume type VMAX_ISCSI is associated with the ISCSI_backend, and the type VMAX_FC is associated with the FC_backend.

    Create the /etc/cinder/cinder_emc_config_CONF_GROUP_ISCSI.xml file. You do not need to restart the service for this change.

    Add the following lines to the XML file:

    VMAX All Flash and Hybrid
    <?xml version="1.0" encoding="UTF-8" ?>
    <EMC>
      <EcomServerIp>1.1.1.1</EcomServerIp>
      <EcomServerPort>00</EcomServerPort>
      <EcomUserName>user1</EcomUserName>
      <EcomPassword>password1</EcomPassword>
      <PortGroups>
        <PortGroup>OS-PORTGROUP1-PG</PortGroup>
        <PortGroup>OS-PORTGROUP2-PG</PortGroup>
      </PortGroups>
      <Array>111111111111</Array>
      <Pool>SRP_1</Pool>
      <ServiceLevel>Diamond</ServiceLevel>
      <Workload>OLTP</Workload>
    </EMC>
    

    Where:

Note

VMAX Hybrid supports Optimized, Diamond, Platinum, Gold, Silver, Bronze, and NONE service levels. VMAX All Flash supports Diamond and NONE. Both support DSS_REP, DSS, OLTP_REP, OLTP, and NONE workloads.

EcomServerIp
IP address of the ECOM server which is packaged with SMI-S.
EcomServerPort
Port number of the ECOM server which is packaged with SMI-S.
EcomUserName and EcomPassword
Credentials for the ECOM server.
PortGroups
Supplies the names of VMAX port groups that have been pre-configured to expose volumes managed by this backend. Each supplied port group should have sufficient number and distribution of ports (across directors and switches) as to ensure adequate bandwidth and failure protection for the volume connections. PortGroups can contain one or more port groups of either iSCSI or FC ports. When a dynamic masking view is created by the VMAX driver, the port group is chosen randomly from the PortGroup list, to evenly distribute load across the set of groups provided. Make sure that the PortGroups set contains either all FC or all iSCSI port groups (for a given back end), as appropriate for the configured driver (iSCSI or FC).
Array
Unique VMAX array serial number.
Pool
Unique pool name within a given array. For back ends not using FAST automated tiering, the pool is a single pool that has been created by the administrator. For back ends exposing FAST policy automated tiering, the pool is the bind pool to be used with the FAST policy.
ServiceLevel
VMAX All Flash and Hybrid only. The Service Level manages the underlying storage to provide expected performance. Omitting the ServiceLevel tag means that non FAST storage groups will be created instead (storage groups not associated with any service level).
Workload
VMAX All Flash and Hybrid only. When a workload type is added, the latency range is reduced due to the added information. Omitting the Workload tag means the latency range will be the widest for its SLO type.

FC Zoning with VMAX

Zone Manager is required when there is a fabric between the host and array. This is necessary for larger configurations where pre-zoning would be too complex and open-zoning would raise security concerns.

iSCSI with VMAX

  • Make sure the iscsi-initiator-utils package is installed on all Compute nodes.

Note

You can only ping the VMAX iSCSI target ports when there is a valid masking view. An attach operation creates this masking view.

VMAX masking view and group naming info

Masking view names

Masking views are dynamically created by the VMAX FC and iSCSI drivers using the following naming conventions. [protocol] is either I for volumes attached over iSCSI or F for volumes attached over Fiber Channel.

VMAX All Flash and Hybrid

OS-[shortHostName]-[SRP]-[SLO]-[workload]-[protocol]-MV

Initiator group names

For each host that is attached to VMAX volumes using the drivers, an initiator group is created or re-used (per attachment type). All initiators of the appropriate type known for that host are included in the group. At each new attach volume operation, the VMAX driver retrieves the initiators (either WWNNs or IQNs) from OpenStack and adds or updates the contents of the Initiator Group as required. Names are of the following format. [protocol] is either I for volumes attached over iSCSI or F for volumes attached over Fiber Channel.

OS-[shortHostName]-[protocol]-IG

Note

Hosts attaching to OpenStack managed VMAX storage cannot also attach to storage on the same VMAX that are not managed by OpenStack.

FA port groups

VMAX array FA ports to be used in a new masking view are chosen from the list provided in the EMC configuration file.

Storage group names

As volumes are attached to a host, they are either added to an existing storage group (if it exists) or a new storage group is created and the volume is then added. Storage groups contain volumes created from a pool (either single-pool or FAST-controlled), attached to a single host, over a single connection type (iSCSI or FC). [protocol] is either I for volumes attached over iSCSI or F for volumes attached over Fiber Channel.

VMAX All Flash and Hybrid

OS-[shortHostName]-[SRP]-[SLO]-[Workload]-[protocol]-SG

Interval and Retries

By default, Interval and Retries are 10 seconds and 60 retries respectively. These determine how long (Interval) and how many times (Retries) a user is willing to wait for a single SMIS call, 10*60=300seconds. Depending on usage, these may need to be overriden by the user in the XML file. For example, if performance is a factor, then the Interval should be decreased to check the job status more frequently, and if multiple concurrent provisioning requests are issued then Retries should be increased so calls will not timeout prematurely.

In the example below, the driver checks every 5 seconds for the status of the job. It will continue checking for 120 retries before it times out.

Add the following lines to the XML file:

VMAX All Flash and Hybrid

<?xml version="1.0" encoding="UTF-8" ?>
<EMC>
  <EcomServerIp>1.1.1.1</EcomServerIp>
  <EcomServerPort>00</EcomServerPort>
  <EcomUserName>user1</EcomUserName>
  <EcomPassword>password1</EcomPassword>
  <PortGroups>
    <PortGroup>OS-PORTGROUP1-PG</PortGroup>
    <PortGroup>OS-PORTGROUP2-PG</PortGroup>
  </PortGroups>
  <Array>111111111111</Array>
  <Pool>SRP_1</Pool>
  <Interval>5</Interval>
  <Retries>120</Retries>
</EMC>

SSL support

Note

The ECOM component in Solutions Enabler enforces SSL in 8.3.0.1 or later. By default, this port is 5989.

  1. Get the CA certificate of the ECOM server. This pulls the CA cert file and saves it as .pem file. The ECOM server IP address or hostname is my_ecom_host. The sample name of the .pem file is ca_cert.pem:

    # openssl s_client -showcerts -connect my_ecom_host:5989 </dev/null 2>/dev/null|openssl x509 -outform PEM >ca_cert.pem
    
  2. Copy the pem file to the system certificate directory:

    # cp ca_cert.pem /usr/share/ca-certificates/ca_cert.crt
    
  3. Update CA certificate database with the following commands:

    # sudo dpkg-reconfigure ca-certificates
    

    Note

    Check that the new ca_cert.crt will activate by selecting ask on the dialog. If it is not enabled for activation, use the down and up keys to select, and the space key to enable or disable.

    # sudo update-ca-certificates
    
  4. Update /etc/cinder/cinder.conf to reflect SSL functionality by adding the following to the back end block. my_location is the location of the .pem file generated in step one:

    driver_ssl_cert_verify = True
    driver_use_ssl = True
    

    If you skip steps two and three, you must add the location of you .pem file.

    driver_ssl_cert_verify = True
    driver_use_ssl = True
    driver_ssl_cert_path = /my_location/ca_cert.pem
    
  5. Update EcomServerIp to ECOM host name and EcomServerPort to secure port (5989 by default) in /etc/cinder/cinder_emc_config_<conf_group>.xml.

    Note

    When specifying the ECOM host name in the XML file, it is the host name and not the fully qualified domain name (FQDN) you use.

    For example:

    • Host name - ecom_dev
    • Domain name - openstack.prod.com
    • FQDN - eocm_dev.openstack.prod.com

Oversubscription support

Oversubscription support requires the /etc/cinder/cinder.conf to be updated with two additional tags max_over_subscription_ratio and reserved_percentage. In the sample below, the value of 2.0 for max_over_subscription_ratio means that the pools in oversubscribed by a factor of 2, or 200% oversubscribed. The reserved_percentage is the high water mark where by the physical remaining space cannot be exceeded. For example, if there is only 4% of physical space left and the reserve percentage is 5, the free space will equate to zero. This is a safety mechanism to prevent a scenario where a provisioning request fails due to insufficient raw space.

The parameter max_over_subscription_ratio and reserved_percentage are optional.

To set these parameter go to the configuration group of the volume type in /etc/cinder/cinder.conf.

[VMAX_ISCSI_SILVER]
cinder_emc_config_file = /etc/cinder/cinder_emc_config_VMAX_ISCSI_SILVER.xml
volume_driver = cinder.volume.drivers.dell_emc.vmax.iscsi.VMAXISCSIDriver
volume_backend_name = VMAX_ISCSI_SILVER
max_over_subscription_ratio = 2.0
reserved_percentage = 10

For the second iteration of over subscription, take into account the EMCMaxSubscriptionPercent property on the pool. This value is the highest that a pool can be oversubscribed.

Scenario 1

EMCMaxSubscriptionPercent is 200 and the user defined max_over_subscription_ratio is 2.5, the latter is ignored. Oversubscription is 200%.

Scenario 2

EMCMaxSubscriptionPercent is 200 and the user defined max_over_subscription_ratio is 1.5, 1.5 equates to 150% and is less than the value set on the pool. Oversubscription is 150%.

Scenario 3

EMCMaxSubscriptionPercent is 0. This means there is no upper limit on the pool. The user defined max_over_subscription_ratio is 1.5. Oversubscription is 150%.

Scenario 4

EMCMaxSubscriptionPercent is 0. max_over_subscription_ratio is not set by the user. We recommend to default to upper limit, this is 150%.

Note

If FAST is set and multiple pools are associated with a FAST policy, then the same rules apply. The difference is, the TotalManagedSpace and EMCSubscribedCapacity for each pool associated with the FAST policy are aggregated.

Scenario 5

EMCMaxSubscriptionPercent is 200 on one pool. It is 300 on another pool. The user defined max_over_subscription_ratio is 2.5. Oversubscription is 200% on the first pool and 250% on the other.

QoS (Quality of Service) support

Quality of service(QoS) has traditionally been associated with network bandwidth usage. Network administrators set limitations on certain networks in terms of bandwidth usage for clients. This enables them to provide a tiered level of service based on cost. The cinder QoS offers similar functionality based on volume type setting limits on host storage bandwidth per service offering. Each volume type is tied to specific QoS attributes that are unique to each storage vendor. QoS enforcement in cinder is done either at the hypervisor (front end), the storage subsystem (back end), or both. The VMAX driver only supports the storage subsystem (back end) or the combination of hypervisor (front end) and the storage subsystem (back end), but never just hypervisor (front end). The VMAX driver offers the following attributes:

  • By I/O limit per second (IOPS)
  • By limiting throughput per second (MB/S)
  • Dynamic distribution
  • The VMAX offers modification of QoS at the Storage Group level

USE CASE 1 - Default values

Prerequisites - VMAX

  • Host I/O Limit (MB/Sec) - No Limit
  • Host I/O Limit (IO/Sec) - No Limit
  • Set Dynamic Distribution - N/A
Prerequisites - Block Storage (cinder) back end (storage group)
Key Value
maxIOPS 4000
maxMBPS 4000
DistributionType Always
  1. Create QoS Specs with the prerequisite values above:

    $ openstack volume qos create --consumer back-end \
                                  --property maxIOPS=4000 \
                                  --property maxMBPS=4000 \
                                  --property DistributionType=Always \
                                  SILVER
    
  2. Associate QoS specs with specified volume type:

    $ openstack volume qos associate SILVER VOLUME_TYPE
    
  3. Create volume with the volume type indicated above:

    $ openstack volume create --size 1 --type VOLUME_TYPE TEST_VOLUME
    

Outcome - VMAX (storage group)

  • Host I/O Limit (MB/Sec) - 4000
  • Host I/O Limit (IO/Sec) - 4000
  • Set Dynamic Distribution - Always

Outcome - Block Storage (cinder)

Volume is created against volume type and QoS is enforced with the parameters above.

USE CASE 2 - Preset limits

Prerequisites - VMAX

  • Host I/O Limit (MB/Sec) - 2000
  • Host I/O Limit (IO/Sec) - 2000
  • Set Dynamic Distribution - Never
Prerequisites - Block Storage (cinder) back end (storage group)
Key Value
maxIOPS 4000
maxMBPS 4000
DistributionType Always
  1. Create QoS specifications with the prerequisite values above:

    $ openstack volume qos create --property maxIOPS=4000 maxMBPS=4000 DistributionType=Always SILVER
    
  2. Associate QoS specifications with specified volume type:

    $ openstack volume qos associate SILVER VOLUME_TYPE
    
  3. Create volume with the volume type indicated above:

    $ openstack volume create --size 1 --type VOLUME_TYPE TEST_VOLUME
    

Outcome - VMAX (storage group)

  • Host I/O Limit (MB/Sec) - 4000
  • Host I/O Limit (IO/Sec) - 4000
  • Set Dynamic Distribution - Always

Outcome - Block Storage (cinder)

Volume is created against volume type and QoS is enforced with the parameters above.

USE CASE 3 - Preset limits

Prerequisites - VMAX

  • Host I/O Limit (MB/Sec) - No Limit
  • Host I/O Limit (IO/Sec) - No Limit
  • Set Dynamic Distribution - N/A
Prerequisites - Block Storage (cinder) back end (storage group)
Key Value
DistributionType Always
  1. Create QoS specifications with the prerequisite values above:

    $ openstack volume qos create --property DistributionType=Always SILVER
    
  2. Associate QoS specifications with specified volume type:

    $ openstack volume qos associate SILVER VOLUME_TYPE
    
  3. Create volume with the volume type indicated above:

    $ openstack volume create --size 1 --type VOLUME_TYPE TEST_VOLUME
    

Outcome - VMAX (storage group)

  • Host I/O Limit (MB/Sec) - No Limit
  • Host I/O Limit (IO/Sec) - No Limit
  • Set Dynamic Distribution - N/A

Outcome - Block Storage (cinder)

Volume is created against volume type and there is no QoS change.

USE CASE 4 - Preset limits

Prerequisites - VMAX

  • Host I/O Limit (MB/Sec) - No Limit
  • Host I/O Limit (IO/Sec) - No Limit
  • Set Dynamic Distribution - N/A
Prerequisites - Block Storage (cinder) back end (storage group)
Key Value
DistributionType OnFailure
  1. Create QoS specifications with the prerequisite values above:

    $ openstack volume qos create --property DistributionType=OnFailure SILVER
    
  2. Associate QoS specifications with specified volume type:

    $ openstack volume qos associate SILVER VOLUME_TYPE
    
  3. Create volume with the volume type indicated above:

    $ openstack volume create --size 1 --type VOLUME_TYPE TEST_VOLUME
    

Outcome - VMAX (storage group)

  • Host I/O Limit (MB/Sec) - No Limit
  • Host I/O Limit (IO/Sec) - No Limit
  • Set Dynamic Distribution - N/A

Outcome - Block Storage (cinder)

Volume is created against volume type and there is no QoS change.

iSCSI multipathing support

  • Install open-iscsi on all nodes on your system
  • Do not install EMC PowerPath as they cannot co-exist with native multipath software
  • Multipath tools must be installed on all nova compute nodes

On Ubuntu:

# apt-get install open-iscsi           #ensure iSCSI is installed
# apt-get install multipath-tools      #multipath modules
# apt-get install sysfsutils sg3-utils #file system utilities
# apt-get install scsitools            #SCSI tools

On openSUSE and SUSE Linux Enterprise Server:

# zipper install open-iscsi           #ensure iSCSI is installed
# zipper install multipath-tools      #multipath modules
# zipper install sysfsutils sg3-utils #file system utilities
# zipper install scsitools            #SCSI tools

On Red Hat Enterprise Linux and CentOS:

# yum install iscsi-initiator-utils   #ensure iSCSI is installed
# yum install device-mapper-multipath #multipath modules
# yum install sysfsutils sg3-utils    #file system utilities
# yum install scsitools               #SCSI tools

Multipath configuration file

The multipath configuration file may be edited for better management and performance. Log in as a privileged user and make the following changes to /etc/multipath.conf on the Compute (nova) node(s).

devices {
# Device attributed for EMC VMAX
    device {
            vendor "EMC"
            product "SYMMETRIX"
            path_grouping_policy multibus
            getuid_callout "/lib/udev/scsi_id --page=pre-spc3-83 --whitelisted --device=/dev/%n"
            path_selector "round-robin 0"
            path_checker tur
            features "0"
            hardware_handler "0"
            prio const
            rr_weight uniform
            no_path_retry 6
            rr_min_io 1000
            rr_min_io_rq 1
    }
}

You may need to reboot the host after installing the MPIO tools or restart iSCSI and multipath services.

On Ubuntu:

# service open-iscsi restart
# service multipath-tools restart

On openSUSE, SUSE Linux Enterprise Server, Red Hat Enterprise Linux, and CentOS:

# systemctl restart open-iscsi
# systemctl restart multipath-tools
$ lsblk
NAME                                       MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                                          8:0    0     1G  0 disk
..360000970000196701868533030303235 (dm-6) 252:6    0     1G  0 mpath
sdb                                          8:16   0     1G  0 disk
..360000970000196701868533030303235 (dm-6) 252:6    0     1G  0 mpath
vda                                        253:0    0     1T  0 disk

OpenStack configurations

On Compute (nova) node, add the following flag in the [libvirt] section of /etc/nova/nova.conf:

iscsi_use_multipath = True

On cinder controller node, set the multipath flag to true in /etc/cinder/cinder.conf:

use_multipath_for_image_xfer = True

Restart nova-compute and cinder-volume services after the change.

Verify you have multiple initiators available on the compute node for I/O

  1. Create a 3GB VMAX volume.

  2. Create an instance from image out of native LVM storage or from VMAX storage, for example, from a bootable volume

  3. Attach the 3GB volume to the new instance:

    $ multipath -ll
    mpath102 (360000970000196700531533030383039) dm-3 EMC,SYMMETRIX
    size=3G features='1 queue_if_no_path' hwhandler='0' wp=rw
    '-+- policy='round-robin 0' prio=1 status=active
    33:0:0:1 sdb 8:16 active ready running
    '- 34:0:0:1 sdc 8:32 active ready running
    
  4. Use the lsblk command to see the multipath device:

    $ lsblk
    NAME                                       MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
    sdb                                          8:0    0     3G  0 disk
    ..360000970000196700531533030383039 (dm-6) 252:6    0     3G  0 mpath
    sdc                                          8:16   0     3G  0 disk
    ..360000970000196700531533030383039 (dm-6) 252:6    0     3G  0 mpath
    vda
    

Consistency group support

Consistency Groups operations are performed through the CLI using v2 of the cinder API.

/etc/cinder/policy.json may need to be updated to enable new API calls for Consistency groups.

Note

Even though the terminology is ‘Consistency Group’ in OpenStack, a Storage Group is created on the VMAX, and should not be confused with a VMAX Consistency Group which is an SRDF feature. The Storage Group is not associated with any Service Level.

Operations

  • Create a Consistency Group:

    cinder --os-volume-api-version 2 consisgroup-create [--name <name>]
    [--description <description>] [--availability-zone <availability-zone>]
    <volume-types>
    
    $ cinder --os-volume-api-version 2 consisgroup-create --name bronzeCG2 volume_type_1
    
  • List Consistency Groups:

    cinder consisgroup-list [--all-tenants [<0|1>]]
    
    $ cinder consisgroup-list
    
  • Show a Consistency Group:

    cinder consisgroup-show <consistencygroup>
    
    $ cinder consisgroup-show 38a604b7-06eb-4202-8651-dbf2610a0827
    
  • Update a consistency Group:

    cinder consisgroup-update [--name <name>] [--description <description>]
    [--add-volumes <uuid1,uuid2,......>] [--remove-volumes <uuid3,uuid4,......>]
    <consistencygroup>
    

    Change name:

    $ cinder consisgroup-update --name updated_name 38a604b7-06eb-4202-8651-dbf2610a0827
    

    Add volume(s) to a Consistency Group:

    $ cinder consisgroup-update --add-volumes af1ae89b-564b-4c7f-92d9-c54a2243a5fe 38a604b7-06eb-4202-8651-dbf2610a0827
    

    Delete volume(s) from a Consistency Group:

    $ cinder consisgroup-update --remove-volumes af1ae89b-564b-4c7f-92d9-c54a2243a5fe 38a604b7-06eb-4202-8651-dbf2610a0827
    
  • Create a snapshot of a Consistency Group:

    cinder cgsnapshot-create [--name <name>] [--description <description>]
    <consistencygroup>
    
    $ cinder cgsnapshot-create 618d962d-2917-4cca-a3ee-9699373e6625
    
  • Delete a snapshot of a Consistency Group:

    cinder cgsnapshot-delete <cgsnapshot> [<cgsnapshot> ...]
    
    $ cinder cgsnapshot-delete 618d962d-2917-4cca-a3ee-9699373e6625
    
  • Delete a Consistency Group:

    cinder consisgroup-delete [--force] <consistencygroup> [<consistencygroup> ...]
    
    $ cinder consisgroup-delete --force 618d962d-2917-4cca-a3ee-9699373e6625
    
  • Create a Consistency group from source:

    cinder consisgroup-create-from-src [--cgsnapshot <cgsnapshot>]
    [--source-cg <source-cg>] [--name <name>] [--description <description>]
    
    $ cinder consisgroup-create-from-src --source-cg 25dae184-1f25-412b-b8d7-9a25698fdb6d
    
    $ cinder consisgroup-create-from-src --cgsnapshot 618d962d-2917-4cca-a3ee-9699373e6625
    
  • You can also create a volume in a consistency group in one step:

    $ openstack volume create [--consistency-group consistency-group>]
      [--description <description>]  [--type <volume-type>]
      [--availability-zone <availability-zone>]  [--size <size>] <name>
    
    $ openstack volume create --type volume_type_1 --consistency-group \
      1de80c27-3b2f-47a6-91a7-e867cbe36462 --size 1 cgBronzeVol
    

Workload Planner (WLP)

VMAX Hybrid allows you to manage application storage by using Service Level Objectives (SLO) using policy based automation rather than the tiering in the VMAX2. The VMAX Hybrid comes with up to 6 SLO policies defined. Each has a set of workload characteristics that determine the drive types and mixes which will be used for the SLO. All storage in the VMAX Array is virtually provisioned, and all of the pools are created in containers called Storage Resource Pools (SRP). Typically there is only one SRP, however there can be more. Therefore, it is the same pool we will provision to but we can provide different SLO/Workload combinations.

The SLO capacity is retrieved by interfacing with Unisphere Workload Planner (WLP). If you do not set up this relationship then the capacity retrieved is that of the entire SRP. This can cause issues as it can never be an accurate representation of what storage is available for any given SLO and Workload combination.

Enabling WLP on Unisphere

  1. To enable WLP on Unisphere, click on the array‣Performance‣Settings.
  2. Set both the Real Time and the Root Cause Analysis.
  3. Click Register.

Note

This should be set up ahead of time (allowing for several hours of data collection), so that the Unisphere for VMAX Performance Analyzer can collect rated metrics for each of the supported element types.

Using TestSmiProvider to add statistics access point

After enabling WLP you must then enable SMI-S to gain access to the WLP data:

  1. Connect to the SMI-S Provider using TestSmiProvider.

  2. Navigate to the Active menu.

  3. Type reg and enter the noted responses to the questions:

    (EMCProvider:5989) ? reg
    Current list of statistics Access Points: ?
    Note: The current list will be empty if there are no existing Access Points.
    Add Statistics Access Point {y|n} [n]: y
    HostID [l2se0060.lss.emc.com]: ?
    Note: Enter the Unisphere for VMAX location using a fully qualified Host ID.
    Port [8443]: ?
    Note: The Port default is the Unisphere for VMAX default secure port. If the secure port
    is different for your Unisphere for VMAX setup, adjust this value accordingly.
    User [smc]: ?
    Note: Enter the Unisphere for VMAX username.
    Password [smc]: ?
    Note: Enter the Unisphere for VMAX password.
    
  4. Type reg again to view the current list:

    (EMCProvider:5988) ? reg
    Current list of statistics Access Points:
    HostIDs:
    l2se0060.lss.emc.com
    PortNumbers:
    8443
    Users:
    smc
    Add Statistics Access Point {y|n} [n]: n
    

Attach and detach snapshots

Attach snapshot and Detach snapshot are used internally by non-disruptive backup and backup snapshot. As of the Newton release, it is possible to back up a volume, but not possible to directly back up a snapshot. Volume back up functionality has been available ever since backups were introduced into the Cinder service. The ability to back up a volume directly is valuable because you can back up a volume in one step. Users can take snapshots from the volumes as a way to protect their data. These snapshots reside on the storage backend itself. Providing a way to backup snapshots directly allows users to protect the snapshots taken from the volumes on a backup device, separately from the storage backend.

There are users who have taken many snapshots and would like a way to protect these snapshots. The functionality to backup snapshots provides another layer of data protection.

Please refer to backup and restore volumes and snapshots <https://docs.openstack.org/admin-guide/blockstorage-volume-backups.html> for more more information.

Enable attach and detach snapshot functionality

  1. Ensure that the cinder-backup service is running.

  2. The backup driver for the swift back end performs a volume backup to an object storage system. To enable the swift backup driver, include the following option in the cinder.conf file:

    backup_driver = cinder.backup.drivers.swift
    
  3. In order to force the volume to run attach and detach on the snapshot and not the volume you need to put the following key-value pair in the [DEFAULT] section of the cinder.conf:

    backup_use_same_host = True
    

Note

You may need to increase the message queue timeout value which is 60 by default in the [DEFAULT] section of the cinder.conf. This is necessary because the snapshot may take more than this time.
rpc_response_timeout = 240

Use case 1 - Create a volume backup when the volume is in-use

  1. Create a bootable volume and launch it so the volume status is in-use.

  2. Create a backup of the volume, where VOLUME is the volume name or volume ID. This will initiate a snapshot attach and a snapshot detach on a temporary snapshot:

    openstack backup create --force VOLUME_ID
    
  3. For example:

    openstack backup create --force cba1ca83-b857-421a-87c3-df81eb9ea8ab
    

Use case 2 - Restore a backup of a volume

  1. Restore the backup from Use case 1, where BACKUP_ID is the identifier of the backup from Use case 1.

    openstack backup restore BACKUP_ID VOLUME_ID
    
  2. For example:

    openstack backup restore ec7e17ec-ae3c-4495-9ee6-7f45c9a89572 cba1ca83-b857-421a-87c3-df81eb9ea8ab
    

Once complete, launch the back up as an instance, and it should be a bootable volume.

Use case 3 - Create a backup of a snapshot

  1. Create a volume.

  2. Create a snapshot of the volume.

  3. Create a backup of the snapshot, where VOLUME is the volume name or volume ID, SNAPSHOT_ID is the ID of the volume’s snapshot. This will initiate a snapshot attach and a snapshot detach on the snapshot.

    openstack backup create [--snapshot SNAPSHOT_ID} VOLUME
    
  4. For example:

    openstack backup create --snapshot 6ab440c2-80ef-4f16-ac37-2d9db938732c 9fedfc4a-5f25-4fa1-8d8d-d5bec91f72e0
    

Use case 4 - Restore backup of a snapshot

  1. Restore the backup where BACKUP_ID is the identifier of the backup from Use case 3.

    openstack backup restore BACKUP_ID
    
  2. For example:

    openstack backup restore ec7e17ec-ae3c-4495-9ee6-7f45c9a89572
    

All Flash compression support

On an All Flash array, the creation of any storage group has a compressed attribute by default. Setting compression on a storage group does not mean that all the devices will be immediately compressed. It means that for all incoming writes compression will be considered. Setting compression off on a storage group does not mean that all the devices will be uncompressed. It means all the writes to compressed tracks will make these tracks uncompressed.

Note

This feature is only applicable for All Flash arrays, 250F, 450F or 850F.

Use case 1 - Compression disabled create, attach, detach, and delete volume

  1. Create a new volume type called VMAX_COMPRESSION_DISABLED.
  2. Set an extra spec volume_backend_name.
  3. Set a new extra spec storagetype:disablecompression = True.
  4. Create a new volume.
  5. Check in Unisphere or symcli to see if the volume exists in storage group OS-<srp>-<servicelevel>-<workload>-CD-SG, and compression is disabled on that storage group.
  6. Attach the volume to an instance. Check in Unisphere or symcli to see if the volume exists in storage group OS-<shorthostname>-<srp>-<servicelevel>-<workload>-CD-SG, and compression is disabled on that storage group.
  7. Detach volume from instance. Check in Unisphere or symcli to see if the volume exists in storage group OS-<srp>-<servicelevel>-<workload>-CD-SG, and compression is disabled on that storage group.
  8. Delete the volume. If this was the last volume in the OS-<srp>-<servicelevel>-<workload>-CD-SG storage group, it should also be deleted.

Use case 2 - Compression disabled create, delete snapshot and delete volume

  1. Repeat steps 1-5 of Use case 1.
  2. Create a snapshot. The volume should now exist in OS-<srp>-<servicelevel>-<workload>-CD-SG.
  3. Delete the snapshot. The volume should be removed from OS-<srp>-<servicelevel>-<workload>-CD-SG.
  4. Delete the volume. If this volume is the last volume in OS-<srp>-<servicelevel>-<workload>-CD-SG, it should also be deleted.

Use case 3 - Retype from compression disabled to compression enabled

  1. Repeat steps 1-4 of Use case 1.
  2. Create a new volume type. For example VMAX_COMPRESSION_ENABLED.
  3. Set extra spec volume_backend_name as before.
  4. Set the new extra spec’s compression as storagetype:disablecompression = False or DO NOT set this extra spec.
  5. Retype from volume type VMAX_COMPRESSION_DISABLED to VMAX_COMPRESSION_ENABLED.
  6. Check in Unisphere or symcli to see if the volume exists in storage group OS-<srp>-<servicelevel>-<workload>-SG, and compression is enabled on that storage group.

Note

If extra spec storagetype:disablecompression is set on a hybrid, it is ignored because compression is not a feature on a VMAX3 hybrid.

Volume replication support

Configure the source and target arrays

  1. Configure a synchronous SRDF group between the chosen source and target arrays for the VMAX cinder driver to use. The source array must correspond with the <Array> entry in the VMAX XML file.

  2. Select both the director and the ports for the SRDF emulation to use on both sides. Bear in mind that network topology is important when choosing director endpoints. Currently, the only supported mode is Synchronous.

    Note

    For full failover functionality, the source and target VMAX arrays must be discovered and managed by the same SMI-S/ECOM server, locally connected for example. This SMI-S/ ECOM server cannot be embedded - it can be installed on a physical server or a VM hosted by an ESX server only.

    Note

    With both arrays being managed by the one SMI-S server, it is the cloud storage administrators responsibility to account for a DR scenario where the management (SMI-S) server goes down as well as the primary array. In that event, the details and credentials of a back-up SMI-S server can be passed in to the XML file, and the VMAX cinder driver can be rebooted. It would be advisable to have the SMI-S server at a third location (separate from both arrays) if possible.

    Note

    If the source and target arrays are not managed by the same management server (that is, the target array is remotely connected to server), in the event of a full disaster scenario (for example, the primary array is completely lost and all connectivity to it is gone), the SMI-S server would no longer be able to contact the target array. In this scenario, the volumes would be automatically failed over to the target array, but administrator intervention would be required to either; configure the target (remote) array as local to the current SMI-S server, or enter the details to the XML file of a second SMI-S server, which is locally connected to the target array, and restart the cinder volume service.

  3. Enable replication in /etc/cinder/cinder.conf. To enable the replication functionality in VMAX cinder driver, it is necessary to create a replication volume-type. The corresponding back-end stanza in the cinder.conf for this volume-type must then include a replication_device parameter. This parameter defines a single replication target array and takes the form of a list of key value pairs.

    enabled_backends = VMAX_FC_REPLICATION
    [VMAX_FC_REPLICATION]
    volume_driver = cinder.volume.drivers.dell_emc.vmax.fc.VMAXFCDriver
    cinder_emc_config_file = /etc/cinder/cinder_emc_config_VMAX_FC_REPLICATION.xml
    volume_backend_name = VMAX_FC_REPLICATION
    replication_device = target_device_id:000197811111, remote_port_group:os-failover-pg, remote_pool:SRP_1, rdf_group_label: 28_11_07, allow_extend:False
    
    • target_device_id is a unique VMAX array serial number of the target array. For full failover functionality, the source and target VMAX arrays must be discovered and managed by the same SMI-S/ECOM server. That is, locally connected. Follow the instructions in the SMI-S release notes.
    • remote_port_group is the name of a VMAX port group that has been pre-configured to expose volumes managed by this backend in the event of a failover. Make sure that this portgroup contains either all FC or all iSCSI port groups (for a given back end), as appropriate for the configured driver (iSCSI or FC).
    • remote_pool is the unique pool name for the given target array.
    • rdf_group_label is the name of a VMAX SRDF group (Synchronous) that has been pre-configured between the source and target arrays.
    • allow_extend is a flag for allowing the extension of replicated volumes. To extend a volume in an SRDF relationship, this relationship must first be broken, both the source and target volumes are then independently extended, and then the replication relationship is re-established. As the SRDF link must be severed, due caution should be exercised when performing this operation. If not explicitly set, this flag defaults to False.

    Note

    Service Level and Workload: An attempt will be made to create a storage group on the target array with the same service level and workload combination as the primary. However, if this combination is unavailable on the target (for example, in a situation where the source array is a Hybrid, the target array is an All Flash, and an All Flash incompatible SLO like Bronze is configured), no SLO will be applied.

    Note

    The VMAX cinder drivers can support a single replication target per back-end, that is we do not support Concurrent SRDF or Cascaded SRDF. Ensure there is only a single .replication_device. entry per back-end stanza.

  4. Create a replication-enabled volume type. Once the replication_device parameter has been entered in the VMAX backend entry in the cinder.conf, a corresponding volume type needs to be created replication_enabled property set. See above Setup VMAX drivers for details.

    $ openstack volume type set --property replication_enabled = ``<is> True`` VMAX_FC_REPLICATION
    

Volume replication interoperability with other features

Most features are supported, except for the following:

  • There is no OpenStack Consistency Group support for replication-enabled VMAX volumes.

  • Storage-assisted retype operations on replication-enabled VMAX volumes (moving from a non-replicated type to a replicated-type and vice-versa. Moving to another SLO/workload combination, for example) are not supported.

  • The image volume cache functionality is supported (enabled by setting image_volume_cache_enabled = True), but one of two actions must be taken when creating the cached volume:

    • The first boot volume created on a backend (which will trigger the cached volume to be created) should be the smallest necessary size. For example, if the minimum size disk to hold an image is 5GB, create the first boot volume as 5GB.
    • Alternatively, ensure that the allow_extend option in the replication_device parameter is set to True.

    This is because the initial boot volume is created at the minimum required size for the requested image, and then extended to the user specified size.

Failover host

In the event of a disaster, or where there is required downtime, upgrade of the primary array for example, the administrator can issue the failover host command to failover to the configured target:

$ cinder failover-host cinder_host@VMAX_FC_REPLICATION#Diamond+SRP_1+000192800111

If the primary array becomes available again, you can initiate a failback using the same command and specifying --backend_id default:

$ cinder failover-host \
  cinder_host@VMAX_FC_REPLICATION#Diamond+SRP_1+000192800111 \
  --backend_id default

Volume retype - storage assisted volume migration

Volume retype with storage assisted migration is supported now for VMAX3 arrays. Cinder requires that for storage assisted migration, a volume cannot be retyped across backends. For using storage assisted volume retype, follow these steps:

  1. Add the parameter multi_pool_support to the configuration group in the /etc/cinder/cinder.conf file and set it to True.

    [CONF_GROUP_FC]
    volume_driver = cinder.volume.drivers.dell_emc.vmax.fc.VMAXFCDriver
    cinder_emc_config_file = /etc/cinder/cinder_emc_config_CONF_GROUP_FC.xml
    volume_backend_name = FC_backend
    multi_pool_support = True
    
  2. Configure a single backend per SRP for the VMAX (Only VMAX3 arrays). This is different from the regular configuration where one backend is configured per service level.

  3. Create the /etc/cinder/cinder_emc_config_CONF_GROUP_FC.xml and add the following lines to the XML for VMAX All Flash and Hybrid.

    <?xml version = "1.0" encoding = "UTF-8" ?>
    <EMC>
       <EcomServerIp>1.1.1.1</EcomServerIp>
       <EcomServerPort>00</EcomServerPort>
       <EcomUserName>user1</EcomUserName>
       <EcomPassword>password1</EcomPassword>
       <PortGroups>
          <PortGroup>OS-PORTGROUP1-PG</PortGroup>
          <PortGroup>OS-PORTGROUP2-PG</PortGroup>
       </PortGroups>
       <Array>111111111111</Array>
       <Pool>SRP_1</Pool>
    </EMC>
    

    Note

    There is no need to specify the Service Level and Workload in the XML file. A single XML file corresponding to the backend is sufficient instead of creating one each for the desired Service Level and Workload combination.

  4. Once the backend is configured in the cinder.conf file and the VMAX specific configuration XML created, restart the cinder volume service for the changes to take place.

  5. Run the command cinder get-pools --detail to query for the pool information. This should list all the available Service Level and Workload combinations available for the SRP as pools belonging to the same backend.

  6. Use the following examples of OpenStack commands to create various volume types. The below example demonstrates creating a volume type for Diamond Service Level and OLTP workload.

    $ openstack volume type create VMAX_FC_DIAMOND_OLTP
    $ openstack volume type set --property volume_backend_name=FC_backend VMAX_FC_DIAMOND_OLTP
    $ openstack volume type set --property pool_name=Diamond+OLTP+SRP_1+111111111111 VMAX_FC_DIAMOND_OLTP
    

    Note

    Create as many volume types as the number of Service Level and Workload (available) combinations which you are going to use for provisioning volumes. The pool_name is the additional property which has to be set and is of the format: <ServiceLevel>+<Workload>+<SRP>+<Array ID>. This can be obtained from the output of the cinder get-pools --detail.

  7. For migrating a volume from one Service Level or Workload combination to another, use volume retype with the migration-policy to on-demand. The target volume type should have the same volume_backend_name configured and should have the desired pool_name to which you are trying to retype to.

    $ cinder retype --migration-policy on-demand <volume> <volume-type>
    
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