==============
VMware vSphere
==============

Introduction
------------

OpenStack Compute supports the VMware vSphere product family and enables access
to advanced features such as vMotion, High Availability, and Dynamic Resource
Scheduling (DRS).

This section describes how to configure VMware-based virtual machine images for
launch. The VMware driver supports vCenter version 5.5.0 and later.

The VMware vCenter driver enables the ``nova-compute`` service to communicate
with a VMware vCenter server that manages one or more ESX host clusters.  The
driver aggregates the ESX hosts in each cluster to present one large hypervisor
entity for each cluster to the Compute scheduler.  Because individual ESX hosts
are not exposed to the scheduler, Compute schedules to the granularity of
clusters and vCenter uses DRS to select the actual ESX host within the cluster.
When a virtual machine makes its way into a vCenter cluster, it can use all
vSphere features.

The following sections describe how to configure the VMware vCenter driver.


High-level architecture
-----------------------

The following diagram shows a high-level view of the VMware driver
architecture:

.. rubric:: VMware driver architecture

.. figure:: /_static/images/vmware-nova-driver-architecture.jpg
   :width: 100%

As the figure shows, the OpenStack Compute Scheduler sees three hypervisors
that each correspond to a cluster in vCenter.  ``nova-compute`` contains the
VMware driver. You can run with multiple ``nova-compute`` services. It is
recommended to run with one ``nova-compute`` service per ESX cluster thus
ensuring that while Compute schedules at the granularity of the
``nova-compute`` service it is also in effect able to schedule at the cluster
level. In turn the VMware driver inside ``nova-compute`` interacts with the
vCenter APIs to select an appropriate ESX host within the cluster. Internally,
vCenter uses DRS for placement.

The VMware vCenter driver also interacts with the Image service to copy VMDK
images from the Image service back-end store.  The dotted line in the figure
represents VMDK images being copied from the OpenStack Image service to the
vSphere data store.  VMDK images are cached in the data store so the copy
operation is only required the first time that the VMDK image is used.

After OpenStack boots a VM into a vSphere cluster, the VM becomes visible in
vCenter and can access vSphere advanced features. At the same time, the VM is
visible in the OpenStack dashboard and you can manage it as you would any other
OpenStack VM. You can perform advanced vSphere operations in vCenter while you
configure OpenStack resources such as VMs through the OpenStack dashboard.

The figure does not show how networking fits into the architecture. For
details, see :ref:`vmware-networking`.


Configuration overview
----------------------

To get started with the VMware vCenter driver, complete the following
high-level steps:

#. Configure vCenter. See :ref:`vmware-prereqs`.

#. Configure the VMware vCenter driver in the ``nova.conf`` file.
   See :ref:`vmware-vcdriver`.

#. Load desired VMDK images into the Image service. See :ref:`vmware-images`.

#. Configure the Networking service (neutron). See :ref:`vmware-networking`.

.. _vmware-prereqs:

Prerequisites and limitations
-----------------------------

Use the following list to prepare a vSphere environment that runs with the
VMware vCenter driver:

Copying VMDK files
  In vSphere 5.1, copying large image files (for example, 12 GB and greater)
  from the Image service can take a long time.  To improve performance, VMware
  recommends that you upgrade to VMware vCenter Server 5.1 Update 1 or later.
  For more information, see the `Release Notes
  <https://www.vmware.com/support/vsphere5/doc/vsphere-vcenter-server-51u1-release-notes.html#resolvedissuescimapi>`_.

DRS
  For any cluster that contains multiple ESX hosts, enable DRS and enable fully
  automated placement.

Shared storage
  Only shared storage is supported and data stores must be shared among all
  hosts in a cluster. It is recommended to remove data stores not intended for
  OpenStack from clusters being configured for OpenStack.

Clusters and data stores
  Do not use OpenStack clusters and data stores for other purposes.  If you do,
  OpenStack displays incorrect usage information.

Networking
  The networking configuration depends on the desired networking model.  See
  :ref:`vmware-networking`.

Security groups
  If you use the VMware driver with OpenStack Networking and the NSX plug-in,
  security groups are supported.

  .. note::

     The NSX plug-in is the only plug-in that is validated for vSphere.

VNC
  The port range 5900 - 6105 (inclusive) is automatically enabled for VNC
  connections on every ESX host in all clusters under OpenStack control.

  .. note::

     In addition to the default VNC port numbers (5900 to 6000) specified in
     the above document, the following ports are also used: 6101, 6102, and
     6105.

  You must modify the ESXi firewall configuration to allow the VNC ports.
  Additionally, for the firewall modifications to persist after a reboot, you
  must create a custom vSphere Installation Bundle (VIB) which is then
  installed onto the running ESXi host or added to a custom image profile used
  to install ESXi hosts. For details about how to create a VIB for persisting
  the firewall configuration modifications, see `Knowledge Base
  <http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&amp;cmd=displayKC&amp;externalId=2007381>`_.

  .. note::

     The VIB can be downloaded from `openstack-vmwareapi-team/Tools
     <https://github.com/openstack-vmwareapi-team/Tools>`_.

To use multiple vCenter installations with OpenStack, each vCenter must be
assigned to a separate availability zone. This is required as the OpenStack
Block Storage VMDK driver does not currently work across multiple vCenter
installations.


VMware vCenter service account
------------------------------

OpenStack integration requires a vCenter service account with the following
minimum permissions. Apply the permissions to the ``Datacenter`` root object,
and select the :guilabel:`Propagate to Child Objects` option.

.. list-table:: vCenter permissions tree
   :header-rows: 1
   :widths: 12, 12, 40, 36

   * - All Privileges
     -
     -
     -
   * -
     - Datastore
     -
     -
   * -
     -
     - Allocate space
     -
   * -
     -
     - Browse datastore
     -
   * -
     -
     - Low level file operation
     -
   * -
     -
     - Remove file
     -
   * -
     - Extension
     -
     -
   * -
     -
     - Register extension
     -
   * -
     - Folder
     -
     -
   * -
     -
     - Create folder
     -
   * -
     - Host
     -
     -
   * -
     -
     - Configuration
     -
   * -
     -
     -
     - Maintenance
   * -
     -
     -
     - Network configuration
   * -
     -
     -
     - Storage partition configuration
   * -
     - Network
     -
     -
   * -
     -
     - Assign network
     -
   * -
     - Resource
     -
     -
   * -
     -
     - Assign virtual machine to resource pool
     -
   * -
     -
     - Migrate powered off virtual machine
     -
   * -
     -
     - Migrate powered on virtual machine
     -
   * -
     - Virtual Machine
     -
     -
   * -
     -
     - Configuration
     -
   * -
     -
     -
     - Add existing disk
   * -
     -
     -
     - Add new disk
   * -
     -
     -
     - Add or remove device
   * -
     -
     -
     - Advanced
   * -
     -
     -
     - CPU count
   * -
     -
     -
     - Change resource
   * -
     -
     -
     - Disk change tracking
   * -
     -
     -
     - Host USB device
   * -
     -
     -
     - Memory
   * -
     -
     -
     - Modify device settings
   * -
     -
     -
     - Raw device
   * -
     -
     -
     - Remove disk
   * -
     -
     -
     - Rename
   * -
     -
     -
     - Set annotation
   * -
     -
     -
     - Swapfile placement
   * -
     -
     - Interaction
     -
   * -
     -
     -
     - Configure CD media
   * -
     -
     -
     - Power Off
   * -
     -
     -
     - Power On
   * -
     -
     -
     - Reset
   * -
     -
     -
     - Suspend
   * -
     -
     - Inventory
     -
   * -
     -
     -
     - Create from existing
   * -
     -
     -
     - Create new
   * -
     -
     -
     - Move
   * -
     -
     -
     - Remove
   * -
     -
     -
     - Unregister
   * -
     -
     - Provisioning
     -
   * -
     -
     -
     - Clone virtual machine
   * -
     -
     -
     - Customize
   * -
     -
     -
     - Create template from virtual machine
   * -
     -
     - Snapshot management
     -
   * -
     -
     -
     - Create snapshot
   * -
     -
     -
     - Remove snapshot
   * -
     - Profile-driven storage
     -
     -
   * -
     -
     - Profile-driven storage view
     -
   * -
     - Sessions
     -
     -
   * -
     -
     -
     - Validate session
   * -
     -
     -
     - View and stop sessions
   * -
     - vApp
     -
     -
   * -
     -
     - Export
     -
   * -
     -
     - Import
     -


.. _vmware-vcdriver:

VMware vCenter driver
---------------------

Use the VMware vCenter driver (VMwareVCDriver) to connect OpenStack Compute
with vCenter. This recommended configuration enables access through vCenter to
advanced vSphere features like vMotion, High Availability, and Dynamic Resource
Scheduling (DRS).

VMwareVCDriver configuration options
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add the following VMware-specific configuration options to the ``nova.conf``
file:

.. code-block:: ini

   [DEFAULT]
   compute_driver = vmwareapi.VMwareVCDriver

   [vmware]
   host_ip = <vCenter hostname or IP address>
   host_username = <vCenter username>
   host_password = <vCenter password>
   cluster_name = <vCenter cluster name>
   datastore_regex = <optional datastore regex>

.. note::

   * Clusters: The vCenter driver can support only a single cluster.  Clusters
     and data stores used by the vCenter driver should not contain any VMs
     other than those created by the driver.

   * Data stores: The ``datastore_regex`` setting specifies the data stores to
     use with Compute.  For example, ``datastore_regex="nas.*"`` selects all
     the data stores that have a name starting with "nas".  If this line is
     omitted, Compute uses the first data store returned by the vSphere API. It
     is recommended not to use this field and instead remove data stores that
     are not intended for OpenStack.

   * Reserved host memory: The ``reserved_host_memory_mb`` option value is 512
     MB by default. However, VMware recommends that you set this option to 0 MB
     because the vCenter driver reports the effective memory available to the
     virtual machines.

   * The vCenter driver generates instance name by instance ID.  Instance name
     template is ignored.

   * The minimum supported vCenter version is 5.5.0.  Starting in the OpenStack
     Ocata release any version lower than 5.5.0 will be logged as a warning. In
     the OpenStack Pike release this will be enforced.

A ``nova-compute`` service can control one or more clusters containing multiple
ESXi hosts, making ``nova-compute`` a critical service from a high availability
perspective. Because the host that runs ``nova-compute`` can fail while the
vCenter and ESX still run, you must protect the ``nova-compute`` service
against host failures.

.. note::

   Many ``nova.conf`` options are relevant to libvirt but do not apply to this
   driver.


.. _vmware-images:

Images with VMware vSphere
--------------------------

The vCenter driver supports images in the VMDK format. Disks in this format can
be obtained from VMware Fusion or from an ESX environment.  It is also possible
to convert other formats, such as qcow2, to the VMDK format using the
``qemu-img`` utility. After a VMDK disk is available, load it into the Image
service. Then, you can use it with the VMware vCenter driver. The following
sections provide additional details on the supported disks and the commands
used for conversion and upload.

Supported image types
~~~~~~~~~~~~~~~~~~~~~

Upload images to the OpenStack Image service in VMDK format.  The following
VMDK disk types are supported:

* ``VMFS Flat Disks`` (includes thin, thick, zeroedthick, and
  eagerzeroedthick). Note that once a VMFS thin disk is exported from VMFS to a
  non-VMFS location, like the OpenStack Image service, it becomes a
  preallocated flat disk. This impacts the transfer time from the Image service
  to the data store when the full preallocated flat disk, rather than the thin
  disk, must be transferred.

* ``Monolithic Sparse disks``. Sparse disks get imported from the Image service
  into ESXi as thin provisioned disks. Monolithic Sparse disks can be obtained
  from VMware Fusion or can be created by converting from other virtual disk
  formats using the ``qemu-img`` utility.

* ``Stream-optimized disks``. Stream-optimized disks are compressed sparse
  disks. They can be obtained from VMware vCenter/ESXi when exporting vm to
  ovf/ova template.

The following table shows the ``vmware_disktype`` property that applies to each
of the supported VMDK disk types:

.. list-table:: OpenStack Image service disk type settings
   :header-rows: 1

   * - vmware_disktype property
     - VMDK disk type
   * - sparse
     - Monolithic Sparse
   * - thin
     - VMFS flat, thin provisioned
   * - preallocated (default)
     - VMFS flat, thick/zeroedthick/eagerzeroedthick
   * - streamOptimized
     - Compressed Sparse

The ``vmware_disktype`` property is set when an image is loaded into the Image
service. For example, the following command creates a Monolithic Sparse image
by setting ``vmware_disktype`` to ``sparse``:

.. code-block:: console

   $ openstack image create \
     --disk-format vmdk \
     --container-format bare \
     --property vmware_disktype="sparse" \
     --property vmware_ostype="ubuntu64Guest" \
     ubuntu-sparse < ubuntuLTS-sparse.vmdk

.. note::

   Specifying ``thin`` does not provide any advantage over ``preallocated``
   with the current version of the driver. Future versions might restore the
   thin properties of the disk after it is downloaded to a vSphere data store.

The following table shows the ``vmware_ostype`` property that applies to each
of the supported guest OS:

.. note::

   If a glance image has a ``vmware_ostype`` property which does not correspond
   to a valid VMware guestId, VM creation will fail, and a warning will be
   logged.

.. list-table:: OpenStack Image service OS type settings
   :header-rows: 1

   * - vmware_ostype property
     - Retail Name
   * - asianux3_64Guest
     - Asianux Server 3 (64 bit)
   * - asianux3Guest
     - Asianux Server 3
   * - asianux4_64Guest
     - Asianux Server 4 (64 bit)
   * - asianux4Guest
     - Asianux Server 4
   * - darwin64Guest
     - Darwin 64 bit
   * - darwinGuest
     - Darwin
   * - debian4_64Guest
     - Debian GNU/Linux 4 (64 bit)
   * - debian4Guest
     - Debian GNU/Linux 4
   * - debian5_64Guest
     - Debian GNU/Linux 5 (64 bit)
   * - debian5Guest
     - Debian GNU/Linux 5
   * - dosGuest
     - MS-DOS
   * - freebsd64Guest
     - FreeBSD x64
   * - freebsdGuest
     - FreeBSD
   * - mandrivaGuest
     - Mandriva Linux
   * - netware4Guest
     - Novell NetWare 4
   * - netware5Guest
     - Novell NetWare 5.1
   * - netware6Guest
     - Novell NetWare 6.x
   * - nld9Guest
     - Novell Linux Desktop 9
   * - oesGuest
     - Open Enterprise Server
   * - openServer5Guest
     - SCO OpenServer 5
   * - openServer6Guest
     - SCO OpenServer 6
   * - opensuse64Guest
     - openSUSE (64 bit)
   * - opensuseGuest
     - openSUSE
   * - os2Guest
     - OS/2
   * - other24xLinux64Guest
     - Linux 2.4x Kernel (64 bit) (experimental)
   * - other24xLinuxGuest
     - Linux 2.4x Kernel
   * - other26xLinux64Guest
     - Linux 2.6x Kernel (64 bit) (experimental)
   * - other26xLinuxGuest
     - Linux 2.6x Kernel (experimental)
   * - otherGuest
     - Other Operating System
   * - otherGuest64
     - Other Operating System (64 bit) (experimental)
   * - otherLinux64Guest
     - Linux (64 bit) (experimental)
   * - otherLinuxGuest
     - Other Linux
   * - redhatGuest
     - Red Hat Linux 2.1
   * - rhel2Guest
     - Red Hat Enterprise Linux 2
   * - rhel3_64Guest
     - Red Hat Enterprise Linux 3 (64 bit)
   * - rhel3Guest
     - Red Hat Enterprise Linux 3
   * - rhel4_64Guest
     - Red Hat Enterprise Linux 4 (64 bit)
   * - rhel4Guest
     - Red Hat Enterprise Linux 4
   * - rhel5_64Guest
     - Red Hat Enterprise Linux 5 (64 bit) (experimental)
   * - rhel5Guest
     - Red Hat Enterprise Linux 5
   * - rhel6_64Guest
     - Red Hat Enterprise Linux 6 (64 bit)
   * - rhel6Guest
     - Red Hat Enterprise Linux 6
   * - sjdsGuest
     - Sun Java Desktop System
   * - sles10_64Guest
     - SUSE Linux Enterprise Server 10 (64 bit) (experimental)
   * - sles10Guest
     - SUSE Linux Enterprise Server 10
   * - sles11_64Guest
     - SUSE Linux Enterprise Server 11 (64 bit)
   * - sles11Guest
     - SUSE Linux Enterprise Server 11
   * - sles64Guest
     - SUSE Linux Enterprise Server 9 (64 bit)
   * - slesGuest
     - SUSE Linux Enterprise Server 9
   * - solaris10_64Guest
     - Solaris 10 (64 bit) (experimental)
   * - solaris10Guest
     - Solaris 10 (32 bit) (experimental)
   * - solaris6Guest
     - Solaris 6
   * - solaris7Guest
     - Solaris 7
   * - solaris8Guest
     - Solaris 8
   * - solaris9Guest
     - Solaris 9
   * - suse64Guest
     - SUSE Linux (64 bit)
   * - suseGuest
     - SUSE Linux
   * - turboLinux64Guest
     - Turbolinux (64 bit)
   * - turboLinuxGuest
     - Turbolinux
   * - ubuntu64Guest
     - Ubuntu Linux (64 bit)
   * - ubuntuGuest
     - Ubuntu Linux
   * - unixWare7Guest
     - SCO UnixWare 7
   * - win2000AdvServGuest
     - Windows 2000 Advanced Server
   * - win2000ProGuest
     - Windows 2000 Professional
   * - win2000ServGuest
     - Windows 2000 Server
   * - win31Guest
     - Windows 3.1
   * - win95Guest
     - Windows 95
   * - win98Guest
     - Windows 98
   * - windows7_64Guest
     - Windows 7 (64 bit)
   * - windows7Guest
     - Windows 7
   * - windows7Server64Guest
     - Windows Server 2008 R2 (64 bit)
   * - winLonghorn64Guest
     - Windows Longhorn (64 bit) (experimental)
   * - winLonghornGuest
     - Windows Longhorn (experimental)
   * - winMeGuest
     - Windows Millennium Edition
   * - winNetBusinessGuest
     - Windows Small Business Server 2003
   * - winNetDatacenter64Guest
     - Windows Server 2003, Datacenter Edition (64 bit) (experimental)
   * - winNetDatacenterGuest
     - Windows Server 2003, Datacenter Edition
   * - winNetEnterprise64Guest
     - Windows Server 2003, Enterprise Edition (64 bit)
   * - winNetEnterpriseGuest
     - Windows Server 2003, Enterprise Edition
   * - winNetStandard64Guest
     - Windows Server 2003, Standard Edition (64 bit)
   * - winNetEnterpriseGuest
     - Windows Server 2003, Enterprise Edition
   * - winNetStandard64Guest
     - Windows Server 2003, Standard Edition (64 bit)
   * - winNetStandardGuest
     - Windows Server 2003, Standard Edition
   * - winNetWebGuest
     - Windows Server 2003, Web Edition
   * - winNTGuest
     - Windows NT 4
   * - winVista64Guest
     - Windows Vista (64 bit)
   * - winVistaGuest
     - Windows Vista
   * - winXPHomeGuest
     - Windows XP Home Edition
   * - winXPPro64Guest
     - Windows XP Professional Edition (64 bit)
   * - winXPProGuest
     - Windows XP Professional

Convert and load images
~~~~~~~~~~~~~~~~~~~~~~~

Using the ``qemu-img`` utility, disk images in several formats (such as,
qcow2) can be converted to the VMDK format.

For example, the following command can be used to convert a `qcow2 Ubuntu
Trusty cloud image <http://cloud-images.ubuntu.com/trusty/
current/trusty-server-cloudimg-amd64-disk1.img>`_:

.. code-block:: console

   $ qemu-img convert -f qcow2 ~/Downloads/trusty-server-cloudimg-amd64-disk1.img \
     -O vmdk trusty-server-cloudimg-amd64-disk1.vmdk

VMDK disks converted through ``qemu-img`` are ``always`` monolithic sparse VMDK
disks with an IDE adapter type. Using the previous example of the Ubuntu Trusty
image after the ``qemu-img`` conversion, the command to upload the VMDK disk
should be something like:

.. code-block:: console

   $ openstack image create \
     --container-format bare --disk-format vmdk \
     --property vmware_disktype="sparse" \
     --property vmware_adaptertype="ide" \
     trusty-cloud < trusty-server-cloudimg-amd64-disk1.vmdk

Note that the ``vmware_disktype`` is set to ``sparse`` and the
``vmware_adaptertype`` is set to ``ide`` in the previous command.

If the image did not come from the ``qemu-img`` utility, the
``vmware_disktype`` and ``vmware_adaptertype`` might be different.  To
determine the image adapter type from an image file, use the following command
and look for the ``ddb.adapterType=`` line:

.. code-block:: console

   $ head -20 <vmdk file name>

Assuming a preallocated disk type and an iSCSI lsiLogic adapter type, the
following command uploads the VMDK disk:

.. code-block:: console

   $ openstack image create \
     --disk-format vmdk \
     --container-format bare \
     --property vmware_adaptertype="lsiLogic" \
     --property vmware_disktype="preallocated" \
     --property vmware_ostype="ubuntu64Guest" \
     ubuntu-thick-scsi < ubuntuLTS-flat.vmdk

Currently, OS boot VMDK disks with an IDE adapter type cannot be attached to a
virtual SCSI controller and likewise disks with one of the SCSI adapter types
(such as, busLogic, lsiLogic, lsiLogicsas, paraVirtual) cannot be attached to
the IDE controller. Therefore, as the previous examples show, it is important
to set the ``vmware_adaptertype`` property correctly. The default adapter type
is lsiLogic, which is SCSI, so you can omit the ``vmware_adaptertype`` property
if you are certain that the image adapter type is lsiLogic.

Tag VMware images
~~~~~~~~~~~~~~~~~

In a mixed hypervisor environment, OpenStack Compute uses the
``hypervisor_type`` tag to match images to the correct hypervisor type.  For
VMware images, set the hypervisor type to ``vmware``.  Other valid hypervisor
types include: ``ironic``, ``lxc``, and ``qemu``.
Note that ``qemu`` is used for both QEMU and KVM hypervisor types.

.. code-block:: console

   $ openstack image create \
     --disk-format vmdk \
     --container-format bare \
     --property vmware_adaptertype="lsiLogic" \
     --property vmware_disktype="preallocated" \
     --property hypervisor_type="vmware" \
     --property vmware_ostype="ubuntu64Guest" \
     ubuntu-thick-scsi < ubuntuLTS-flat.vmdk

Optimize images
~~~~~~~~~~~~~~~

Monolithic Sparse disks are considerably faster to download but have the
overhead of an additional conversion step. When imported into ESX, sparse disks
get converted to VMFS flat thin provisioned disks. The download and conversion
steps only affect the first launched instance that uses the sparse disk image.
The converted disk image is cached, so subsequent instances that use this disk
image can simply use the cached version.

To avoid the conversion step (at the cost of longer download times) consider
converting sparse disks to thin provisioned or preallocated disks before
loading them into the Image service.

Use one of the following tools to pre-convert sparse disks.

vSphere CLI tools
  Sometimes called the remote CLI or rCLI.

  Assuming that the sparse disk is made available on a data store accessible by
  an ESX host, the following command converts it to preallocated format:

  .. code-block:: console

     vmkfstools --server=ip_of_some_ESX_host -i \
       /vmfs/volumes/datastore1/sparse.vmdk \
       /vmfs/volumes/datastore1/converted.vmdk

  Note that the vifs tool from the same CLI package can be used to upload the
  disk to be converted. The vifs tool can also be used to download the
  converted disk if necessary.

``vmkfstools`` directly on the ESX host
  If the SSH service is enabled on an ESX host, the sparse disk can be uploaded
  to the ESX data store through scp and the vmkfstools local to the ESX host
  can use used to perform the conversion.  After you log in to the host through
  ssh, run this command:

  .. code-block:: console

     vmkfstools -i /vmfs/volumes/datastore1/sparse.vmdk /vmfs/volumes/datastore1/converted.vmdk

``vmware-vdiskmanager``
  ``vmware-vdiskmanager`` is a utility that comes bundled with VMware Fusion
  and VMware Workstation. The following example converts a sparse disk to
  preallocated format:

  .. code-block:: console

     '/Applications/VMware Fusion.app/Contents/Library/vmware-vdiskmanager' -r sparse.vmdk -t 4 converted.vmdk

In the previous cases, the converted vmdk is actually a pair of files:

* The descriptor file ``converted.vmdk``.

* The actual virtual disk data file ``converted-flat.vmdk``.

The file to be uploaded to the Image service is ``converted-flat.vmdk``.

Image handling
~~~~~~~~~~~~~~

The ESX hypervisor requires a copy of the VMDK file in order to boot up a
virtual machine. As a result, the vCenter OpenStack Compute driver must
download the VMDK via HTTP from the Image service to a data store that is
visible to the hypervisor. To optimize this process, the first time a VMDK file
is used, it gets cached in the data store.  A cached image is stored in a
folder named after the image ID.  Subsequent virtual machines that need the
VMDK use the cached version and don't have to copy the file again from the
Image service.

Even with a cached VMDK, there is still a copy operation from the cache
location to the hypervisor file directory in the shared data store.  To avoid
this copy, boot the image in linked_clone mode. To learn how to enable this
mode, see :oslo.config:option:`vmware.use_linked_clone`.

.. note::

   You can also use the ``img_linked_clone`` property (or legacy property
   ``vmware_linked_clone``) in the Image service to override the linked_clone
   mode on a per-image basis.

   If spawning a virtual machine image from ISO with a VMDK disk, the image is
   created and attached to the virtual machine as a blank disk.  In that case
   ``img_linked_clone`` property for the image is just ignored.

If multiple compute nodes are running on the same host, or have a shared file
system, you can enable them to use the same cache folder on the back-end data
store. To configure this action, set the ``cache_prefix`` option in the
``nova.conf`` file. Its value stands for the name prefix of the folder where
cached images are stored.

.. note::

   This can take effect only if compute nodes are running on the same host, or
   have a shared file system.

You can automatically purge unused images after a specified period of time.  To
configure this action, set these options in the :oslo.config:group:`image_cache`
section in the ``nova.conf`` file:

* :oslo.config:option:`image_cache.remove_unused_base_images`
* :oslo.config:option:`image_cache.remove_unused_original_minimum_age_seconds`


.. _vmware-networking:

Networking with VMware vSphere
------------------------------

The VMware driver supports networking with the Networking Service (neutron).
Depending on your installation, complete these configuration steps before you
provision VMs:

#. Before provisioning VMs, create a port group with the same name as the
   ``vmware.integration_bridge`` value in ``nova.conf`` (default is
   ``br-int``). All VM NICs are attached to this port group for management by
   the OpenStack Networking plug-in.


Volumes with VMware vSphere
---------------------------

The VMware driver supports attaching volumes from the Block Storage service.
The VMware VMDK driver for OpenStack Block Storage is recommended and should be
used for managing volumes based on vSphere data stores. For more information
about the VMware VMDK driver, see Cinder's manual on the VMDK Driver (TODO:
this has not yet been imported and published).  Also an
iSCSI volume driver provides limited support and can be used only for
attachments.


Troubleshooting
---------------

Operators can troubleshoot VMware specific failures by correlating OpenStack
logs to vCenter logs. Every RPC call which is made by an OpenStack driver has
an ``opID`` which can be traced in the vCenter logs. For example consider the
following excerpt from a ``nova-compute`` log:

.. code-block:: console

   Aug 15 07:31:09 localhost nova-compute[16683]: DEBUG oslo_vmware.service [-] Invoking Folder.CreateVM_Task with opID=oslo.vmware-debb6064-690e-45ac-b0ae-1b94a9638d1f {{(pid=16683) request_handler /opt/stack/oslo.vmware/oslo_vmware/service.py:355}}

In this case the ``opID`` is
``oslo.vmware-debb6064-690e-45ac-b0ae-1b94a9638d1f`` and we can grep the
vCenter log (usually ``/var/log/vmware/vpxd/vpxd.log``) for it to
find if anything went wrong with the ``CreateVM`` operation.
