VMware Cloud Director Availability™ 4.2 | 10 JUN 2021 | Build 18136536 (Product version:

Check for additions and updates to these release notes.

What's in the Release Notes

The release notes cover the following topics:

What's New

VMware Cloud Director Availability 4.2 introduces the following new features:

  • Stretching On-Premises Layer 2 Networks: The service providers can now stretch the on-premises networks across the cloud site for migrations from the on-premises site to the cloud site that allow network connectivity between already migrated and not yet migrated virtual machines as in the same network segment, with some operations* caveats and limitations. Layer 2 VPN (L2 VPN) stretches the L2 networks across the sites.
  • Migration to VMware Cloud Director service: the new Data Mover Service also called H4DM operates the new VMC data engine that can now migrate workloads to the VMware Cloud Director service after deploying VMware Cloud Director Availability 4.2 in VMware Cloud on AWS, with some operations** caveats and limitations. Both the service providers and their tenants, can use the existing migration flow and migrate their workloads to VMware Cloud Director service after following the new VMware Cloud Director Availability Migration to VMware Cloud Director Service Guide.

In VMware Cloud Director Availability 4.2, you can also now record your screen and optionally your microphone. For more information, see Record Your Screen with the Live Incident Assistant.


VMware Cloud Director Availability 4.2 supports an in-place upgrade directly from versions 4.0, 4.0.1, 4.1.1, and 4.1. For more information, see Upgrading in the Cloud and Upgrading On-Premises.

Caveats and Limitations

Note: The VMware Cloud Director Availability vSphere Client Plug-In requires vSphere Client support. With earlier vSphere versions, to configure replications use the VMware Cloud Director Availability Portal.

In vSphere 7.0 or later, to configure protection or configure replication you can right-click a virtual machine and the replication is always configured through the default on-premises appliance instance. In the plug-in, to replicate through another on-premises appliance instance, on the dashboard activate the other on-premises appliance instance, then configure the replication through it. 

* The Layer 2 VPN sessions have the following limitations in VMware Cloud Director Availability 4.2:

  • In more than one L2 VPN session, do not attempt to use/add the same organization VDC network, or a network segment, or in NSX-T it causes the following error message: Tunnel ID specified for L2 VPN [list] is already used by...
  • The Autonomous Edge cannot distinguish between networks with the same vlan id. Editing the client L2 VPN session and switching from one on-premises network to another with the same vlan id is not reflected in the VMware Cloud Director Availability interface and the original network is still shown as stretched.
  • Stretching on-premises standard switches port groups is not supported. Only DVS port groups are supported for stretching.
  • One Autonomous Edge supports only one client L2 VPN session, stretching a maximum of 14 networks.

** The replications to VMware Cloud Director service in VMware Cloud on AWS, handled by the VMC data engine have the following limitations in VMware Cloud Director Availability 4.2:

  • These replications cannot replicate encrypted virtual machines.
  • These replications cannot replicate virtual machines with attached independent disks.
  • These replications support up to 30 disks per virtual machine, while classic engine replications support up to 60.
  • These replications are not evacuated during 'Evacuate datastore' operations and remain on the same datastore.
  • These replications also do not support: Protection workflows, Policies, reporting and dashboard aggregation. 
  • These replications are not moved during 'Enter maintenance mode' operations. Putting a Cloud Replicator Appliance in maintenance mode does not move these existing replications from that Cloud Replicator Appliance instance, while the 'Enter maintenance mode' operation reports success. Upgrading or rebooting the Cloud Replicator Appliance causes issues for these replications.

For interoperability between paired sites with mismatching VMware Cloud Director Availability versions, see Managing Connections Between Cloud Sites.

For interoperability between VMware Cloud Director Availability and other VMware products, see VMware Product Interoperability Matrices

Configuration Maximums

For the tested uptime, concurrency, and scale limits, see VMware Configuration Maximums.

Supported Browsers

VMware Cloud Director Availability 4.2 supports the following browsers:

  • Google Chrome 91 and later
  • Microsoft Edge Chromium 91 and later
  • Mozilla Firefox 89 and later
  • Safari 14 and later

Resolved Issues

  • VDC group networks are not visible in vApp Replication Network settings page and in the recovery wizards

    VMware Cloud Director 10.2.0 introduces VDC groups. All of the new networks types will not be listed when configuring vApp Replication Network settings or in the failover, test failover, or migration wizards. This issue affects all VMware Cloud Director Availability 4.x versions.

  • In the OpenApi client, GET /backups/{backupId} and GET /diagnostics/bundles/{bundleId} are listed only for documentation purposes

    The two APIs use the standard authentication method, by using a custom header "X-VCAV-Auth" and cannot download a file as they cannot pass the required custom headers when opening a new tab in the Web browser.

  • Cannot set a limit of the number of configured replications when incoming protections are disabled

    When creating or editing a replication policy with incoming protections disabled, you cannot save the value of the Limit of the number of configured replications. With incoming protections enabled, this issue does not apply.

    For example, in the Default Policy the incoming protections by default are disabled, and to configure the value for this maxincoming limit, use the OpenApi Client.

  • Cannot assign a policy to an organization or sync with cloud by using the root user account with hundreds OrgVDCs

    If you have VMware Cloud Director 10.1.1 with hundreds of organizations, in multiple cases, VMware Cloud Director Availability shows errors, caused by the VMware Cloud Director response: BadMessageException: 500: Response header too large

    For example: 

    • After you log in as the root user, in the Assign Policy window after selecting a policy and clicking Sync with Cloud, you see Operation aborted due to an unexpected error.
    • Assigning any policy to an organization shows the same error.
    • Each hour, a scheduled task checks for organizations without an assigned policy and assigns the Default policy to them.
    • Updating any policy synchronizes the Default policy and increases the organization count in the Default policy view in time or after any policy is updated. Any organization without policy gets assigned the Default policy.
    • Installing the plug-in in VMware Cloud Director for eligible tenants: when connecting a Cloud Director instance with that many organizations to the Cloud Service during the plug-in install shows the error FailedToPublishPluginException: Unable to publish the vCloud Availability plugin to the eligible tenants. To install the plug-in, in the Cloud Service management interface, under Settings > Service endpoints > VMware Cloud Director Address click Edit, then Apply.
    • Similarly, under Settings clicking Remove plugin shows the error: FailedToUnpublishPluginException: Could not unpublish the vCloud Availability plugin for one or more tenants. The issue is the same and triggers in case any organization is left with the plug-in installed.
  • Attempting to assign a policy when multiple pages of organizations are listed intermittently fails or replaces the existing policy assignments with the Default Policy

    In the Assign Policy dialog box, selecting organizations and clicking Assign, with more than one page of organizations listed, fails with Cannot read property 'id' of undefined or organizations listed on unvisited pages that were assigned with this policy become assigned with the Default Policy instead.

  • Cannot list the destination storage policies with thousands storage profiles

    When creating a replication to a site with several thousands of storage profiles, the destination storage policies cannot be listed and the replication cannot be created.

  • If configuring a replication fails during independent disk creation, this placeholder disk is not cleaned up from VMware Cloud Director

    The placeholder disk leftover is not cleaned up from VMware Cloud Director when configuring a replication fails at the creation of an independent disk. If, for example, the size of the placeholder named disk is larger than any datastore in the target storage policy can accommodate, you see a message Operation aborted due to an unexpected error. This placeholder disk, while consuming storage is not visible by using VMware Cloud Director query APIs and the independent disk in an error state is visible when browsing the destination OrgVDC.

  • Cannot register the plug-in for versions 4.0.x and 4.1.x in VMware Cloud Director 10.3 or later 

    When using VMware Cloud Director 10.3 or later versions, you cannot register the VMware Cloud Director Availability plug-in for versions 4.0.x and 4.1.x.

Known Issues

  • In vSphere 6.7 the on-premises plug-in caches the VMware Cloud Director Availability On-Premises Appliance on the first registration
    • In vSphere 6.7, after changing the IP address or the certificate of the on-premises appliance, the on-premises plug-in cannot use the on-premises appliance with the updated IP address or certificate. 
    • Also, in vSphere 6.7 if you deploy and register a second on-premises appliance instance, the on-premises plug-in shows it but cannot switch to the second on-premises appliance instance.

    Workaround: To clear the cache of the on-premises plug-in:

    1. Unregister all on-premises appliance instances from the vCenter Server by logging in to their management interface and clicking Settings > Lookup Service Address > Remove.
    2. To clear the stale state out of the cache, log in to the vSphere Client.
    3. Register the on-premises appliance instances again with the vCenter Server by logging in to their management interfaces and clicking Settings > Lookup Service Address > Add.
    4. To see the registrations of the on-premises appliance instances and cache their correct state, log in again to the vSphere Client.
  • Extending the session with System administrator user cannot start outgoing replications from 4.0.x cloud sites to 4.1 or 4.2 cloud sites

    In a cloud site that is running VMware Cloud Director Availability or VMware Cloud Director Availability, if you extend your session to a remote cloud site that is running VMware Cloud Director Availability 4.1 or VMware Cloud Director Availability 4.2 by using a System administrator user, you cannot create outgoing replications to the later site.


    • Extend your session and authenticate as a tenant user to the remote cloud site, that is running version 4.1 or 4.2. Then you can create the outgoing replication from the cloud site that is running version 4.0.x.
    • Alternatively, create the replication from the other site that is running version 4.1 or 4.2, as incoming from the cloud site that is running version 4.0.x.
    • Alternatively, upgrade the cloud site running version 4.0.x to version 4.1 or to version 4.2.
  • From the plug-ins in VMware Cloud Director and in vSphere, cannot record the screen by using the Live Incident Recorder 

    From the context of VMware Cloud Director Availability plug-in in VMware Cloud Director and the VMware Cloud Director Availability vSphere Client Plug-in, attempting to record your screen results in a blank video recording.


    • To successfully capture your screen, log in to the management interface of VMware Cloud Director Availability and start the recording from that context.
    • Alternatively, upgrade to VMware Cloud Director Availability 4.3.1 and start the recording from the plug-in in VMware Cloud Director but not from vSphere.
  • Changing the SLA profile of a replication applies retention policy but does not associate the updated SLA profile with the replication

    After changing the SLA profile of a replication, the retention policy of the new SLA profile applies but the updated SLA profile does not associate with the replication and the SLA profile column displays N/A.

    Workaround: Upgrade to VMware Cloud Director Availability 4.2.1 or later.

  • Tenants cannot start new outgoing replications by using multisite authentication to 4.2.x sites using VMware Cloud Director 10.2 or later

    Starting new outgoing protection or migration as a tenant when using multisite authentication to extend the session to destination sites using VMware Cloud Director Availability 4.2.x and VMware Cloud Director 10.2 or later, completes the task with an error The provided credentials are not valid. message. This issue does not affect the service providers.

    Workaround: Log in to the destination site and configure the same replication as an incoming one.

  • After re-balancing replications, performing a test failover, and other management operations remain indefinitely at 1-2% progress

    To prevent the replication from being corrupted, performing management operations locks the replication before performing any changes to it.

    Re-balancing replications detaches the replication from one Replicator Service instance and attaches it to another instance. In case of an error, this replication lock does not get released.

    As a result, all subsequent management operations, for example, pause, resume, test failover, and others fail with the following error message. 

    Lock acquisition timed out for object: H4-bc6f965c-0be4-4325-9c87-a666ba418e44.

    To verify that this caused the issue, open an SSH connection to the Cloud Replication Management Appliance and check the database.

    psql -U h4postgres -d h4manager -c "select * from task where resource_id = 'H4-bc6f965c-0be4-4325-9c87-a666ba418e44' and state = 'RUNNING' and type = 'switchDestinationReplication';"

    Then, in /opt/vmware/h4/manager/log/manager.log or in one of the log archives verify that the following ERROR message is present.

    Re-attach of replication H4-bc6f965c-0be4-4325-9c87-a666ba418e44 to replicator 1ef53db8-fe7d-4cca-864e-012611273c25 failed.

    Workaround: Restart the Manager Service.

    systemctl restart manager

  • Updating the independent disk size loses its assigned storage policy and is assigned with the default storage policy of the datastore

    When updating the disk size of an independent disk, the disk gets recreated but loses its assigned storage policy. VMware Cloud Director then assigns the default storage policy of the datastore to the resized disk.

    Workaround: Upgrade to VMware Cloud Director Availability 4.3 or later.

  • Active replications keep accumulating RPO violations without reporting errors and might end up as "not configured for replication"

    An active replication might show Virtual machine is not configured for replication. As a result, such replication gets in a stopped state until manually fixed.

    The replications can accumulate RPO violations due to monitoring issues between the Replicator Service and vSphere. This occurs after a false report that the replication is no longer configured at the vSphere side.

    In such cases while the event occurs, the Replicator Service log /opt/vmware/h4/replicator/log contains the following message:

    2022-02-13 20:39:17.162 ERROR - [a3306f0e-8948-4435-ab61-3f41187dc5b1] [hbr-poller3] c.v.h.r.m.source.SourceGroupMonitor : VM replication error vm-45@d1828d07-5103-4905-ab89-28726de59b46com.vmware.vim.binding.vim.fault.ReplicationVmFault: vSphere Replication operation error: Virtual machine is not configured for replication.{code}


    • Reconfigure the affected replications, even without effectively changing the replication configuration. Reconfiguring the replications brings them back in a healthy state.
    • Alternatively, upgrade to VMware Cloud Director Availability 4.3.1.
  • Indefinitely running rebalancing replications between Replicator instances due to failing replication move

    If a replication move fails, regardless between the source or the destination Replicator instance, the rebalance task would not indicate the failure.

    Workaround: Upgrade to VMware Cloud Director Availability 4.3.1.

  • Randomly ordered cloud sites in drop-down menus 

    In the New replication wizard, on the Replications page, and in the Tasks pane the drop-down menus that list the paired cloud sites are not sorted and show the cloud sites in random order on every page visit.On-premises sites are always sorted by name.


    • To find a cloud site in a long list, use the Search text box.
    • Alternatively, upgrade to VMware Cloud Director Availability
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