VMware vSAN 8.0 Update 2 Release Notes

VMware vSAN 8.0 Update 2| 21 SEP 2023| ISO Build 22380479 Check for additions and updates to these release notes.

What's in the Release Notes

These release notes introduce you to new features in VMware vSAN 8.0 Update 2 and provide information about known issues.

What's New

vSAN 8.0 Update 2 introduces the following new features and enhancements: 

• Disaggregated Storage

  Enhanced topologies for disaggregation with vSAN Express Storage Architecture bring feature parity for vSAN OSA and vSAN ESA.

  vSAN ESA support for stretched clusters in disaggregated topology. vSAN ESA supports disaggregation when using vSAN stretched clusters. In addition to supporting several stretched cluster configurations, vSAN also optimizes the network paths for certain topologies to improve the performance capabilities of stretched cluster configurations.

  Support of disaggregation across clusters using multiple vCenter Servers. vSAN 8.0 Update 2 supports disaggregation across environments using multiple vCenter Servers when using vSAN ESA. This enables vSphere or vSAN clusters managed by one vCenter Server to use the storage resources of a vSAN cluster managed by a different vCenter Server..

  vSAN ESA Adaptive Write path for disaggregated storage. Disaggregated deployments get the performance benefits of a new adaptive write path previously introduced in vSAN 8.0 Update 1 for standard ESA based deployments. VMs running on a vSphere or vSAN cluster that consume storage from another vSAN ESA cluster can take advantage of this capability. Adaptive write path technology in a disaggregated environment helps your VMs achieve higher throughput and lower latency, and do so automatically in real time, without any interaction by the administrator.

• Core Platform Enhancements

  Integrated File Services for Cloud Native and traditional workloads. vSAN 8.0 Update 2 supports vSAN File Service on vSAN Express Storage Architecture. File service clients can benefit from performance and efficiency enhancements provided by vSAN ESA.

  Adaptive Write Path optimizations in vSAN ESA. vSAN ESA introduces an adaptive write path that helps the cluster ingest and process data more quickly. This optimization improves performance for workloads driving high I/O to single object (VMDK), and also improves aggregate cluster performance.

  Increased number of VM's per host in vSAN ESA clusters (up to 500/host). vSAN 8.0 Update 2 supports up to 500 VMs per host VM on vSAN ESA clusters, provided the underlying hardware infrastructure can support it. Now you can leverage NVMe-based high performance hardware platforms optimized for the latest generation of CPUs with high core densities, and consolidate more VMs per host.

  New ReadyNode profile and support for read-intensive devices for vSAN ESA. vSAN ESA announces the availability of new ReadyNode profiles designed for small data centers and edge environments with lower overall hardware requirements on a per-node basis. This release also introduces support for read-intensive storage devices.

  vSAN ESA support for encryption deep rekey. vSAN clusters using data-at-rest encryption have the ability to perform a deep rekey operation. A deep rekey decrypts the data that has been encrypted and stored on a vSAN cluster using the old encryption key, and re-encrypts the data using newly issued encryption keys prior to storing it on the vSAN cluster.

• Enriched Operations

  vSAN ESA prescriptive disk claim. vSAN ESA includes a prescriptive disk claim process that further simplifies management of storage devices in each host in a vSAN cluster. This feature provides consistency to the disk claiming process during initial deployment and cluster expansion.

  Capacity reporting enhancements. Overhead breakdown in vSAN ESA space reporting displays both the ESA object overhead and the original file system overhead.

  Auto-Policy management improvements in vSAN ESA. Enhanced auto-policy management feature determines if the default storage policy needs to be adjusted when a user adds or removes a host from a cluster. If vSAN identifies a need to change the default storage policy, it triggers a health check warning. You can make the change with a simple click at which time vSAN reconfigures the cluster with the new policy.

  Skyline Health remediation enhancements. vSAN Skyline Health helps you reduce resolution times by providing deployment-specific guidance along with more prescriptive guidance on how to resolve issues.

  Key expiration for clusters with data-at-rest encryption. vSAN 8.0 Update 2 supports the use of KMS servers with a key expiration attribute used for assigning an expiration date to a Key Encryption Key (KEK).

  I/O top contributors enhancements. vSAN Performance Service has improved the process to find performance hot spots over a customizable time period to help you diagnose performance issues while using multiple types of sources for analysis (VMs, host disks, and so on).

  I/O Trip Analyzer supported on two node clusters and stretched clusters. vSAN 8.0 Update 2 has enhanced the I/O Trip Analyzer to report on workloads in a vSAN stretched cluster. Now you can determine where the primary source of latency is occurring in a vSAN stretched cluster, as well as latencies in other parts of the stack that can contribute to the overall latency experienced by the VM.

  Easier configuration for two node clusters and stretched clusters. Several new features to help management of two node and stretched cluster deployments.

  • Witness host traffic configured in the vSphere Client.​

  • Support for medium sized witness host appliance in vSAN ESA.

  • Support in vLCM to manage lifecycle of shared witness host appliance types.

• Cloud Native Storage

  CSI snapshot support for TKG service. Cloud Native Storage introduces CSI snapshot support for TKG Service, enabling K8s users and backup vendors to take persistent volume snapshots on TKGS.

  Data mobility of Cloud Native persistent volumes across datastores. This release introduces built-in migration of persistent volumes across datastores in the vSphere Client.

VMware vSAN Community

Use the vSAN Community Web site to provide feedback and request assistance with any problems you find while using vSAN.

Upgrades for This Release

For instructions about upgrading vSAN, see the VMware vSAN 8.0 Update 2 documentation. 

Note: Before performing the upgrade, please review the most recent version of the VMware Compatibility Guide to validate that the latest vSAN version is available for your platform.

Note: vSAN Express Storage Architecture is available only for new deployments. You cannot upgrade a cluster to vSAN ESA.

vSAN 8.0 Update 2 is a new release that requires a full upgrade to vSphere 8.0 Update 2. Perform the following tasks to complete the upgrade:

1. Upgrade to vCenter Server 8.0 Update 2. For more information, see the VMware vSphere 8.0 Update 2 Release Notes. 

2. Upgrade hosts to ESXi 8.0 Update 2. For more information, see the VMware vSphere 8.0 Update 2 Release Notes. 

3. Upgrade the vSAN on-disk format to version 19.0. If upgrading from on-disk format version 3.0 or later, no data evacuation is required (metadata update only).

4. Upgrade FSVM to enable new File Service features and get all the latest updates.

Note: vSAN retired disk format version 1.0 in vSAN 7.0 Update 1. Disks running disk format version 1.0 are no longer recognized by vSAN. vSAN will block upgrade through vSphere Update Manager, ISO install, or esxcli to vSAN 7.0 Update 1. To avoid these issues, upgrade disks running disk format version 1.0 to a higher version. If you have disks on version 1.0, a health check alerts you to upgrade the disk format version.

Disk format version 1.0 does not have performance and snapshot enhancements, and it lacks support for advanced features including checksum, deduplication and compression, and encryption. For more information about vSAN disk format version, see KB 2148493.

Upgrading the On-disk Format for Hosts with Limited Capacity

During an upgrade of the vSAN on-disk format from version 1.0 or 2.0, a disk group evacuation is performed. The disk group is removed and upgraded to on-disk format version 17.0, and the disk group is added back to the cluster. For two-node or three-node clusters, or clusters without enough capacity to evacuate each disk group, select Allow Reduced Redundancy from the vSphere Client. You also can use the following RVC command to upgrade the on-disk format: vsan.ondisk_upgrade --allow-reduced-redundancy

When you allow reduced redundancy, your VMs are unprotected for the duration of the upgrade, because this method does not evacuate data to the other hosts in the cluster. It removes each disk group, upgrades the on-disk format, and adds the disk group back to the cluster. All objects remain available, but with reduced redundancy.

If you enable deduplication and compression during the upgrade, you can select Allow Reduced Redundancy from the vSphere Client.

Limitations

For information about maximum configuration limits for the vSAN 8.0 Update 2 release, see the Configuration Maximums documentation.

Known Issues

• Failed to consolidate vmdk of vRDM on vSAN ESA cluster

  This issue can occur if you use a vRDM type virtual disk with compatibility mode set to virtual and disk mode set to dependent. In the vSAN ESA datastore, the corresponding virtual disk cannot be consolidated in the snapshot deletion operation after the snapshot is created. This problem can cause the virtual disk to fail to create new snapshot.

  None.

• Encryption operations blocked if Native Key Provider is not backed up

  If you are using Native Key Provider for vSAN data-at-rest encryption, and the Native Key Provider is not backed up, encryption-related reconfiguration operations might fail with the following message: The KMS cluster {kmsCluster} is a Native Key Provider that is not backed up yet.

  Back up the Native Key Provider before enabling data-at-rest encryption.

• Must manually assign storage policy to restored VMs

  If you restore or create a linked clone from a deleted VM, vSAN does not automatically assign a storage policy. The new VM does not have a storage policy.

  Manually assign the storage policy after you create a linked clone VM or restore a VM.

• Japanese text for Skyline Health displays incorrectly when vCenter is air gapped

  This issue can occur when the vCenter network connection is air gapped. Some Japanese text for Skyline Health localizes incorrectly. You might see a message ID such as the following: com.vmware.vsan.health.XXX

  Perform the following steps:

  1. SSH to vCenter.

  2. Open the following file:/etc/vmware-vsan-health/cloudHealthResources/locale/ja/vsanhealthremediation.vmsg

  3. Search for the following:vsan.health.optimaldsdefaultpolicy.htf.0.default.0.des

  4. Merge the two lines into one as shown below, and save the file.

  5. Restart the vSAN health service: /usr/sbin/vmon-cli -r vsan-health

  Before:

  vsan.health.optimaldsdefaultpolicy.htf.0.default.0.des=健全性テーブルに表示される

  vSAN の最適なデータストアのデフォルト ポリシーの「許容される障害の数」または「サイトの耐障害性」の構成 (あるいは両方) が推奨ポリシーと一致しません。

  After:

  vsan.health.optimaldsdefaultpolicy.htf.0.default.0.des=健全性テーブルに表示される vSAN の最適なデータストアのデフォルト ポリシーの「許容される障害の数」または「サイトの耐障害性」の構成 (あるいは両方) が推奨ポリシーと一致しません。

• hostAffinity policy option lost during upgrade

  When you upgrade from vSAN 6.7 to vSAN 8.0, the vCenter Server hostaffinity option value is changed to false.

  Workaround: Set the hostaffinity option back to true to continue using vSAN HostLocal policy for a normal VM.

• Cannot enable File Service if vCenter Server internet connectivity is disabled

  If you disable vCenter Server internet connectivity, the Enable File Service dialog does not display File service agent section and you cannot select OVF.

  Workaround: To enable vCenter Server internet connectivity:

  1. Navigate to Cluster > Configure > vSAN > Internet Connectivity.

  2. Click Edit to open Edit Internet Connectivity dialog.

  3. Select Enable Internet access for all vSAN clusters checkbox and click Apply.

• Cannot deactivate encryption on vSAN ESA

  After you enable data-at-rest encryption on a vSAN ESA cluster, you cannot deactivate it.

  Workaround: None.

• vSAN File Service does not support NFSv4 delegations

  vSAN File Service does not support NFSv4 delegations in this release.

  Workaround: None.

• In stretched cluster, file server with no affinity cannot rebalance

  In the stretched cluster vSAN File Service environment, a file server with no affinity location configured cannot be rebalanced between Preferred ESXi hosts and Non-preferred ESXi hosts.

  Workaround: Set the affinity location of the file server to Preferred or Non-Preferred by editing the file service domain configuration.

• Remediation of ESXi hosts in a vSphere Lifecycle Manager cluster with vSAN fails if vCenter services are deployed on custom ports

  If vCenter Server services are deployed on custom ports in a cluster with vSAN, vSphere DRS, and vSphere HA, remediation of vSphere Lifecycle Manager clusters might fail. This problem is caused by a vSAN resource health check error. ESXi hosts cannot enter maintenance mode, which leads to failing remediation tasks.

  Workaround: None.

• When vSAN file service is enabled, DFC-related operations such as upgrade, enabling encryption or data-efficiency might fail

  When file service is enabled, an agent VM runs on each host. The underlying vSAN object might be placed across multiple diskgroups. When the first diskgroup gets converted, the vSAN object becomes inaccessible and the agent VM is in an invalid state. If you try to delete the VM and redeploy a new VM, the operation fails due to the VM’s invalid state. The VM gets unregistered but the inaccessible object still exists there. When the next diskgroup gets converted, there is a precheck for inaccessible objects in the whole cluster. This check fails the DFC since it finds inaccessible objects of the old agent VM.

  Workaround: Manually remove the inaccessible objects. 

  When such failure happens, you can see the DFC task failure.

  1. Identify the inaccessible objects from the failure task fault information.

  2. To ensure that the objects belong to the agent VM, inspect the hostd log file and confirm that the objects belong to the VM’s object layout.

  3. Log in to the host and use the /usr/lib/vmware/osfs/bin/objtool command to remove the objects manually.

  Note: To prevent this problem, disable file service before performing any DFC-related operation.

• Cannot extract host profile on a vSAN HCI mesh compute-only host

  vSAN host profile plugin does not support vSAN HCI mesh compute-only hosts. If you try to extract the host profile on an HCI mesh compute-only host, the attempt fails. 

  Workaround: None.

• Deleting files in a file share might not be reflected in vSAN capacity view

  The allocated blocks might not be returned back to the vSAN storage instantly after all the files are deleted and hence it would take some time before the reclaimed storage capacity to be updated in vSAN capacity view. When new data is written to the same file share, these deleted blocks might get reused prior to returning them to vSAN storage.

  If unmap is enabled and vSAN deduplication is disabled, the space may not be freed back to vSAN unless 4MB aligned space are freed in VDFS. If unmap is enabled and vSAN deduplication is enabled, space freed by VDFS will be freed back to vSAN with a delay.

  Workaround: To release the storage back to vSAN immediately, delete the file shares. 

• vCenter VM crash on stretched cluster with data-in-transit encryption

  vCenter VM might crash on a vSAN stretched cluster if the vCenter VM is on vSAN with data-in-transit encryption enabled. When all hosts in one site are down and then power on again, the vCenter VM might crash after the failed site returns to service.

  Workaround: Use the following script to resolve this problem: thumbPrintRepair.py  

• vSAN allows a VM to be provisioned across local and remote datastores

  vSphere does not prevent users from provisioning a VM across local and remote datastores in an HCI Mesh environment. For example, you can provision one VMDK on the local vSAN datastore and one VMDK on remote vSAN datastore. This is not supported because vSphere HA is not supported with this configuration.

  Workaround: Do not provision a VM across local and remote datastores.

• The object reformatting task is not progressing

  If object reformatting is needed after an upgrade, a health alert is triggered, and vSAN begins reformatting. vSAN performs this task in batches, and it depends on the amount of transient capacity available in the cluster. When the transient capacity exceeds the maximum limit, vSAN waits for the transient capacity to be freed before proceeding with the reformatting. During this phase, the task might appear to be halted. The health alert will clear and the task will progress when transient capacity is available.

  Workaround: None. The task is working as expected. 

• System VMs cannot be powered-off

  With the release of vSphere Cluster Services (vCLS) in vSphere 7.0 Update 1, a set of system VMs might be placed within the vSAN cluster. These system VMs cannot be powered-off by users. This issue can impact some vSAN workflows, which are documented in the following article: https://kb.vmware.com/s/article/80877

  Workaround: For more information about this issue, refer to this KB article: https://kb.vmware.com/s/article/80483. 

• vSAN File Service cannot be enabled due to an old vSAN on-disk format version

  vSAN File Service cannot be enabled with the vSAN on-disk format version earlier than 11.0 (this is the on-disk format version in vSAN 7.0).

  Workaround: Upgrade the vSAN disk format version before enabling File Service.

• Host failure in hot-plug scenario when drive is reinserted

  During a hot drive removal, VMware native NVMe hot-plug can cause a host failure if the NVMe drive is pulled and reinserted within one minute. This is applicable to both vSphere and vSAN for any new or existing drive reinsertion.

  Workaround: After removing a hot drive, wait for one minute before you reinsert the new or existing drive.

• Cannot place last host in a cluster into maintenance mode, or remove a disk or disk group

  Operations in Full data migration or Ensure accessibility mode might fail without providing guidance to add a new resource, when there is only one host left in the cluster and that host enters maintenance mode. This can also happen when there is only one disk or disk group left in the cluster and that disk or disk group is to be removed.

  Workaround: Before you place the last remaining host in the cluster into maintenance mode with Full data migration or Ensure accessibility mode selected, add another host with the same configuration to the cluster. Before you remove the last remaining disk or disk group in the cluster, add a new disk or disk group with the same configuration and capacity.

• Object reconfiguration workflows might fail due to the lack of capacity if one or more disks or disk groups are almost full

  vSAN resyncs get paused when the disks in non-deduplication clusters or disk groups in deduplication clusters reach a configurable resync pause fullness threshold. This is to avoid filling up the disks with resync I/O. If the disks reach this threshold, vSAN stops reconfiguration workflows, such as EMM, repairs, rebalance, and policy change.

  Workaround: If space is available elsewhere in the cluster, rebalancing the cluster frees up space on the other disks, so that subsequent reconfiguration attempts succeed.

• After recovery from cluster full, VMs can lose HA protection

  In a vSAN cluster that has hosts with disks 100% full, the VMs might have a question pending and hence lose the HA protection. Also, the VMs that had a pending question are not HA protected after recovering from cluster full scenario.

  Workaround: After recovering from vSAN cluster full scenario, perform one of the following actions:

  • Disable and re-enable HA.

  • Reconfigure HA.

  • Power off and power on the VMs.

• Power Off VMs fails with Question Pending

  If a VM has a pending question, you are not allowed to do any VM-related operations until the question is answered.

  Workaround: Try to free the disk space on the relevant volume, and then click Retry.

• When the cluster is full, the IP addresses of VMs either change to IPV6 or become unavailable

  When a vSAN cluster is full with one or more disk groups reaching 100%, there can be a VM pending question that requires user action. If the question is not answered and if the cluster full condition is left unattended, the IP addresses VMs might change to IPv6 or become unavailable. This prevents you from using SSH to access the VMs.  It also prevents you from using the VM console, because the console goes blank after you type root.

  Workaround: None.

• Unable to remove a dedupe enabled disk group after a capacity disk enters PDL state

  When a capacity disk in a dedupe-enabled disk group is removed, or its unique ID changes, or when the device experiences an unrecoverable hardware error, it enters Permanent Device Loss (PDL) state. If you try to remove the disk group, you might see an error message informing you that the action cannot be completed.

  Workaround: Whenever a capacity disk is removed, or its unique ID changes, or when the device experiences an unrecoverable hardware error, wait for a few minutes before trying to remove the disk group.

• In deduplication clusters, reactive rebalancing might not happen when the disks show more than 80% full

  In deduplication clusters, when the disks display more than 80% full on the dashboard, the reactive rebalancing might not start as expected. This is because in deduplication clusters, pending writes and deletes are also considered for calculating the free capacity.

  Workaround: None.

• TRIM/UNMAP commands from Guest OS fail

  If the Guest OS attempts to perform space reclamation during online snapshot consolidation, the TRIM/UNMAP commands fail. This failure keeps space from being reclaimed.

  Workaround: Try to reclaim the space after the online snapshot operation is complete. If subsequent TRIM/UNMAP operations fail, remount the disk.

• Space reclamation from SCSI TRIM/UNMAP is lost when online snapshot consolidation is performed

  Space reclamation achieved from SCSI TRIM/UNMAP commands is lost when you perform online snapshot consolidation. Offline snapshot consolidation does not affect SCSI unmap operation.

  Workaround: Reclaim the space after online snapshot consolidation is complete.

• Host failure when converting data host into witness host

  When you convert a vSAN cluster into a stretched cluster, you must provide a witness host. You can convert a data host into the witness host, but you must use maintenance mode with Full data migration during the process. If you place the host into maintenance mode with Ensure accessibility option, and then configure it as the witness host, the host might fail with a purple diagnostic screen.

  Workaround: Remove the disk group on the witness host and then re-create the disk group.

• Duplicate VM with the same name in vCenter Server when residing host fails during datastore migration

  If a VM is undergoing storage vMotion from vSAN to another datastore, such as NFS, and the host on which it resides encounters a failure on the vSAN network, causing HA failover of the VM, the VM might be duplicated in the vCenter Server. 

  Workaround: Power off the invalid VM and unregister it from the vCenter Server. 

• Reconfiguring an existing stretched cluster under a new vCenter Server causes vSAN to issue a health check warning

  When rebuilding a current stretched cluster under a new vCenter Server, the vSAN cluster health check is red. The following message appears: vSphere cluster members match vSAN cluster members

  Workaround: Use the following procedure to configure the stretched cluster.

  1. Use SSH to log in to the witness host.

  2. Decommission the disks on witness host. Run the following command: esxcli vsan storage remove -s "SSD UUID"

  3. Force the witness host to leave the cluster. Run the following command: esxcli vsan cluster leave

  4. Reconfigure the stretched cluster from the new vCenter Server (Configure > vSAN > Fault Domains & Stretched Cluster).

• Disk format upgrade fails while vSAN resynchronizes large objects

  If the vSAN cluster contains very large objects, the disk format upgrade might fail while the object is resynchronized. You might see the following error message: Failed to convert object(s) on vSAN

  vSAN cannot perform the upgrade until the object is resynchronized. You can check the status of the resynchronization (Monitor > vSAN > Resyncing Components) to verify when the process is complete.

  Workaround: Wait until no resynchronization is pending, then retry the disk format upgrade.

• Powered off VMs appear as inaccessible during witness host replacement

  When you change a witness host in a stretched cluster, VMs that are powered off appear as inaccessible in the vSphere Web Client for a brief time. After the process is complete, powered off VMs appear as accessible. All running VMs appear as accessible throughout the process.

  Workaround: None.

• Cannot place hosts in maintenance mode if they have faulty boot media

  vSAN cannot place hosts with faulty boot media into maintenance mode. The task to enter maintenance mode might fail with an internal vSAN error, due to the inability to save configuration changes. You might see log events similar to the following: Lost Connectivity to the device xxx backing the boot filesystem

  Workaround: Remove disk groups manually from each host, using the Full data evacuation option. Then place the host in maintenance mode.

• After stretched cluster failover, VMs on the preferred site register alert: Failed to failover

  If the secondary site in a stretched cluster fails, VMs failover to the preferred site. VMs already on the preferred site might register the following alert: Failed to failover.

  Workaround: Ignore this alert. It does not impact the behavior of the failover.

• During network partition, components in the active site appear to be absent

  During a network partition in a vSAN two-host or stretched cluster, the vSphere Web Client might display a view of the cluster from the perspective of the non-active site. You might see active components in the primary site displayed as absent.

  Workaround: Use RVC commands to query the state of objects in the cluster. For example: vsan.vm_object_info

• Some objects are non-compliant after force repair

  After you perform a force repair, some objects might not be repaired because the ownership of the objects was transferred to a different node during the process. The force repair might be delayed for those objects.

  Workaround: Attempt the force repair operation after all other objects are repaired and resynchronized. You can wait until vSAN repairs the objects.

• When you move a host from one encrypted cluster to another, and then back to the original cluster, the task fails

  When you move a host from an encrypted vSAN cluster to another encrypted vSAN cluster, then move the host back to the original encrypted cluster, the task might fail. You might see the following message: A general system error occurred: Invalid fault. This error occurs because vSAN cannot re-encrypt data on the host using the original encryption key. After a short time, vCenter Server restores the original key on the host, and all unmounted disks in the vSAN cluster are mounted.

  Workaround: Reboot the host and wait for all disks to get mounted.

• Cannot perform deep rekey if a disk group is unmounted

  Before vSAN performs a deep rekey, it performs a shallow rekey. The shallow rekey fails if an unmounted disk group is present. The deep rekey process cannot begin.

  Workaround: Remount or remove the unmounted disk group.

• Log entries state that firewall configuration has changed

  A new firewall entry appears in the security profile when vSAN encryption is enabled: vsanEncryption. This rule controls how hosts communicate directly to the KMS. When it is triggered, log entries are added to /var/log/vobd.log. You might see the following messages:

  Firewall configuration has changed. Operation 'addIP4' for rule set vsanEncryption succeeded.

  Firewall configuration has changed. Operation 'removeIP4' for rule set vsanEncryption succeeded.

  These messages can be ignored.

  Workaround: None.

• HA failover does not occur after setting Traffic Type option on a vmknic to support witness traffic

  If you set the traffic type option on a vmknic to support witness traffic, vSphere HA does not automatically discover the new setting. You must manually disable and then re-enable HA so it can discover the vmknic. If you configure the vmknic and the vSAN cluster first, and then enable HA on the cluster, it does discover the vmknic.

  Workaround: Manually disable vSphere HA on the cluster, and then re-enable it.

• After resolving network partition, some VM operations on linked clone VMs might fail

  Some VM operations on linked clone VMs that are not producing I/O inside the guest operating system might fail. The operations that might fail include taking snapshots and suspending the VMs. This problem can occur after a network partition is resolved, if the parent base VM's namespace is not yet accessible. When the parent VM's namespace becomes accessible, HA is not notified to power on the VM.

  Workaround: Power cycle VMs that are not actively running I/O operations.

• Cannot place a witness host in Maintenance Mode

  When you attempt to place a witness host in Maintenance Mode, the host remains in the current state and you see the following notification: A specified parameter was not correct.

  Workaround: When placing a witness host in Maintenance Mode, choose the No data migration option.

• Moving the witness host into and then out of a stretched cluster leaves the cluster in a misconfigured state

  If you place the witness host in a vSAN-enabled vCenter cluster, an alarm notifies you that the witness host cannot reside in the cluster. But if you move the witness host out of the cluster, the cluster remains in a misconfigured state.

  Workaround: Move the witness host out of the vSAN stretched cluster, and reconfigure the stretched cluster. For more information, see this article: https://kb.vmware.com/s/article/2130587.

• Unmounted vSAN disks and disk groups displayed as mounted in the vSphere Web Client Operational Status field

  After the vSAN disks or disk groups are unmounted by either running the esxcli vsan storage disk group unmount command or by the vSAN Device Monitor service when disks show persistently high latencies, the vSphere Web Client incorrectly displays the Operational Status field as mounted.

  Workaround: Use the Health field to verify disk status, instead of the Operational Status field.