VMware virtual machines
This section provides considerations and requirements for protecting VMware environments.

When you add a VMware virtual host to the appliance, all VMs are discovered and available for host-level protection. Unitrends uses VMware's vStorage API for Data Protection (VADP) to communicate with ESXi hosts directly or through a vCenter server. You can add ESXi hosts, vCenter servers, or both, to the Unitrends appliance to protect your VMs. Some features require a vCenter (for details, see Additional VMware requirements).
The following information summarizes the high-level steps that protect VMware virtual machines. The information includes links to detailed instructions for each procedure.
Step 1: Review the Best practices and requirements for VMware protection.
Step 2: Add the VMware host to your Unitrends appliance. See Adding a virtual host.
Step 3: Create backup jobs for your VMs:
● To create a job manually, see To create a VMware backup job or To create a VMware backup schedule by using regular expression filters.
● To create a job by using an SLA policy, see To create an SLA policy for VMware assets.
● For a comparison of the manual and SLA policy job creation methods, see About creating backup and backup copy jobs.

Review the information in these topics before implementing VMware host-level protection:

To protect hosted virtual machines, use the To add a virtual host asset procedure to add the following VMware servers to the Unitrends appliance:
Server |
Description |
---|---|
vCenter and managed ESXi servers |
If ESXi servers belong to a vCenter and both are accessible on the network, Unitrends recommends that you add the vCenter and its ESXi servers to the appliance. This enables the appliance to contact the vCenter for management operations (including vMotion support) and to directly contact the ESXi servers for backup and recovery, potentially improving performance by reducing network traffic around the vCenter server. |
vCenter only |
If the ESXi servers are accessible through a vCenter, adding the vCenter to the Unitrends appliance automatically detects all of the associated ESXi servers and their hosted virtual machines. This also enables the Unitrends appliance to be compatible with vMotion, a process through which VMs can migrate among the vCenter’s ESXi servers. In this case, the appliance detects when VMs move between ESXi servers in a cluster and contacts the appropriate server to perform backups. |
ESXi server only |
If ESXi servers are not accessible through a vCenter, or if only a subset of the VMs hosted on the vCenter’s ESXi servers are to be protected, you can add individual ESXi servers. In this case, the appliance contacts the ESXi servers directly for backup and recovery. |

Follow these best practices to protect your VMware virtual machines:
● Adhere to VMware's best practices.
● If you are adding an ESXi or vCenter server to multiple Unitrends appliances, be sure to back up each VM on only one appliance. Backing up the same VM on multiple appliances causes problems with the Change Block Tracking (CBT) used for incremental and differential backups.
● If you add a vCenter, Unitrends recommends also adding the individual ESXi hosts managed by the vCenter.
● Full, differential, and incremental backups are supported for VMs configured with hardware version 7 or higher. CBT must be enabled for differentials and incrementals. See Change Block Tracking (CBT) for details.
● For VMware Windows machines, you can opt to index backups so you can search the VM's backups by filename to quickly recover individual files or folders. See Indexed VMware Windows backups for details.
● A new full backup is required if the VM configuration has changed since the last backup. This includes any configuration changes made to a VM through the hypervisor, such as creating or deleting a snapshot, or adding a new disk.
If the VM configuration has changed since the last backup, the next incremental or differential fails. After this failure, the appliance promotes the next scheduled backup to a full (or displays a message indicating a full is required if an on-demand incremental is attempted). Once a full backup succeeds, subsequent incrementals and differentials run as scheduled.
● In some cases, you may want or need to protect VMs by using file-level backups. For recommendations, see Protecting VMware virtual machines with file-level backups.
● To protect a VM with both host-level and file-level (agent-based) backups, be sure to adhere to the following:
● Ensure that the VM's host-level and file-level jobs do not overlap. Running both simultaneously may lead to undesirable results.
● If protecting hosted SQL or Exchange databases with agent-based application backups, do not use application-aware protection for host-level backups.
● To protect hosted Exchange or SQL simple recovery model applications, use the application-aware feature for host-level backups. See VMware application-aware protection for details.
● If recovery time objectives are important, set up Virtual machine instant recovery to quickly to spin up a failed VM from host-level backups.
● For Recovery Series and Recovery MAX appliances protecting ESXi hosts whose datastores are located on an external SAN, use the SAN-direct backup feature for host-level backups. These backups run more quickly since network bandwidth is not a hit to performance. See VMware SAN-direct backups for details.
● For Unitrends Backup on VMware appliances protecting ESXi hosts whose datastores are located on an external SAN, use the HotAdd backup feature for host-level backups. These backups run more quickly since network bandwidth is not a hit to performance. See VMware HotAdd backups for details.
● For virtual disks hosted on a NAS datastore, running a full backup captures the complete disk (entire virtual disk size).
● Backup failures can occur after a VM’s disks are converted from VHD to VMDK using a third-party tool. For details and solutions for resolving this issue, see Best Practices for Converting Virtual Machine Disks from VHD (Hyper-V) to VMDK (VMware).
● Host-level protection is not supported for the following (use file-level backups instead):
● VMs in a cluster configuration with a fault tolerant disk.
● VMs with dynamic MAC addresses.
● Independent and pass-through disks. These disks are automatically excluded from host-level backups.
● Physical Raw Disk Mapping (RDM) disks. These disks are automatically excluded from host-level backups. (Virtual-mode raw device mapped disks are supported with host-level protection.)
● Sparse disks.
● VMs that use VMware NSX storage.
● VMs hosted on free ESXi versions.

The following requirements must be met for host-level protection of VMware virtual machines.
Item |
Description |
---|---|
ESXi host |
Must be running a paid, licensed version listed in the Unitrends Compatibility and Interoperability Matrix. NOTES ● Host-level protection is not supported for free ESXi versions. To protect VMs hosted on free ESXi, you must install the agent on each VM and run file-level backups. ● Additional requirements and limitations apply to ESXi versions 6, 6.5, 6.7, 7.0, and 8.0. See Additional VMware requirements for details. |
vCenter |
Must be running a licensed version listed in the Unitrends Compatibility and Interoperability Matrix. NOTE Additional requirements and limitations apply to vCenter 6, 6.5, 6.7, 7.0, and 8.0. See Additional VMware requirements for details. |
vCenter or ESXi account privileges |
An account with full administrative privileges is required. The user or group must have the role administrator. You supply these credentials when adding the vCenter or ESXi server to the backup appliance. |
Virtual machine configuration |
Verify the following VM configuration settings: ● VM hardware version must be 4 or higher, and the version must be supported by the VM's ESXi host server. ● VMware tools must be installed and running in the guest operating system to ensure file system and application consistency. ● The VM must not be configured to use VM encryption. NOTE VMware introduced new SATA Virtual Hardware Controllers with vSphere 5.5 and VM Hardware Version 10. See Cannot backup VMs with unsupported devices on ESXi 5.5 host for details on selecting the correct controller when creating new VMs in version 5.5. |
CBT is required to run incremental and differential backups. Running a full backup enables CBT on the VM disks as long as: ● VMware tools are installed and running. ● No snapshots are present on the VM prior to running the full backup. NOTES Only full backups are supported for the following: ● VMs configured with hardware version 4. ● VMs that have more than 16 disks. |
|
You can opt to index a VMware Windows VM's backups so you can quickly search for and recover individual files or folders. With indexed backups, you can use wild card searches to find files/folders across all backups of the virtual machine, rather than mounting and browsing each backup individually. Simply select the files/folders and recover them to any Windows agent-based asset that has been added to your backup appliance. To start indexing a VMware VM's backups, select the Index Backups option in the Edit Assets dialog (see To edit a virtual machine asset for details). Subsequent backups of the VM are indexed. The following requirements and considerations apply: ● The backup appliance must be running release 10.5 or higher. ● Indexing must be enabled on the appliance. Indexing is enabled by default (Configure > Appliances > Edit Appliance > Advanced > General Configuration > indexImageLevelBackups = Yes): ● The target asset where files are recovered must be a Windows asset that has been added to the appliance as an agent-based asset. To recover files to the original location or to another Windows VM, install the Unitrends agent on the VM (see Installing the Windows agent), then add the VM to the backup appliance as an agent-based asset (see To add an agent-based asset). ● Assets with high-frequency backups or with very large file counts can add considerable load to the appliance. Consider appliance load when enabling the index option for these types of assets. ● Filename search of indexed VMware backups is not supported for recovery from imported backup copies. Recover by mounting the imported copy instead (see Windows file-level recovery). ● The index feature is not supported for recovery of ReFS filesystems. Recover by mounting and browsing the backup instead (see Windows file-level recovery). ● To index the backup, the job creates and mounts an object. If a file recovery object is already mounted for the asset, the backup runs but no index is created (as only one object per asset can be mounted at any given time). The resulting backup completes in warning status, with a message indicating that no index was created. |

These additional requirements may apply to your environment.
Item |
Description |
---|---|
vSphere 8.0 |
To protect VMs hosted in vCenter 8.0 or ESXi 8.0, the following requirements and limitations apply: ● The Unitrends appliance must be running release 10.7.5 or higher. ● The vCenter must not be configured to use the Server High Availability feature. High Availability is not supported. ● Hosted VMs must not be configured to use VM encryption. The VM encryption feature and features that require VM encryption (such as virtual TPM) are not supported. ● Hosted VMs must not be configured to use NVDIMM. NVDIMM devices and controllers are not supported. ● Hosted VMs must not be configured to use Microsoft Virtualization Based Security (VBS). VBS is not supported. ● If a vCenter 8.0 VM migrates to a different vCenter, that VM is no longer protected on the original Unitrends schedule. You must manually add it to a new schedule to resume protection. |
vSphere 7.0 |
To protect VMs hosted in vCenter 7.0 or ESXi 7.0, the following requirements and limitations apply: ● The Unitrends appliance must be running release 10.4.6 or higher. ● The vCenter must not be configured to use the Server High Availability feature. High Availability is not supported. ● Hosted VMs must not be configured to use VM encryption. The VM encryption feature and features that require VM encryption (such as virtual TPM) are not supported. ● Hosted VMs must not be configured to use NVDIMM. NVDIMM devices and controllers are not supported. ● Hosted VMs must not be configured to use Microsoft Virtualization Based Security (VBS). VBS is not supported. ● If a vCenter 7.0 VM migrates to a different vCenter, that VM is no longer protected on the original Unitrends schedule. You must manually add it to a new schedule to resume protection. |
vSphere 6.7 |
To protect VMs hosted in vCenter 6.7 or ESXi 6.7, the following requirements and limitations apply: ● The Unitrends appliance must be running release 10.3 or higher. ● The vCenter must not be configured to use the Server High Availability feature. High Availability is not supported. ● Hosted VMs must not be configured to use VM encryption. The VM encryption feature and features that require VM encryption (such as virtual TPM) are not supported. ● Hosted VMs must not be configured to use NVDIMM. NVDIMM devices and controllers are not supported. ● Hosted VMs must not be configured to use Microsoft Virtualization Based Security (VBS). VBS is not supported. ● If a vCenter 6.7 VM migrates to a different vCenter, that VM is no longer protected on the original Unitrends schedule. You must manually add it to a new schedule to resume protection. |
vSphere 6.5 |
To protect VMs hosted in vCenter 6.5 or ESXi 6.5, the following requirements and limitations apply: ● The Unitrends appliance must be running release 9.1.1 or higher. ● The vCenter must not be configured to use the Server High Availability feature. High Availability is not supported. ● Hosted VMs must not be configured to use VM encryption. The VM encryption feature is not supported. ● If a vCenter 6.5 VM migrates to a different vCenter, that VM is no longer protected on the original Unitrends schedule. You must manually add it to a new schedule to resume protection. |
vSphere 6 |
For VMs hosted in vCenter 6 or ESXi 6, the following limitation applies: If a vCenter 6 VM migrates to a different vCenter, that VM is no longer protected on the original Unitrends schedule. You must manually add it to a new schedule to resume protection. |
VMware clusters |
To protect VMware clustered environments, you must add the vCenter to your Unitrends appliance. |
VMware templates |
To protect VMware templates, you must add the vCenter to your Unitrends appliance. |
Virtual-mode raw device mapped disks |
Raw device mapping (RDM) is a feature of ESXi that allows a virtual disk in a VM to be created on a remote iSCSI LUN rather than on a datastore local to the ESX server. VMs with virtual-mode raw device mapped disks are supported with the following limitations: ● The size of the full backup is equal to the entire allocated VM disk size, rather than the used size, since change tracking is not used for RDM backups. ● Any RDM disks are recovered as standard virtual disks. |
SAN-direct backup for Recovery Series and Recovery MAX appliances |
For ESXi hosts whose datastores are located on an external SAN, configure SAN-direct backups. This configuration enables the job to move data directly from the external SAN to the backup appliance during the backup. This direct connection increases backup performance and decreases network bandwidth utilization, affording greater scheduling flexibility as the production network is not used during the backup. See VMware SAN-direct backups for requirements and setup procedures. |
HotAdd backup for Unitrends Backup on VMware appliances |
For ESXi hosts whose datastores are located on an external SAN, configure backups to use the HotAdd transport mode. This configuration enables the job to move data directly from the external SAN to the appliance during the backup. This direct connection increases backup performance and decreases network bandwidth utilization, affording greater scheduling flexibility as the production network is not used during the backup. See VMware HotAdd backups for requirements and setup procedures. |
Application-aware backups |
For Exchange and SQL simple recovery model databases that are hosted on VMware virtual machines, apply local administrator credentials to the VM to run application-aware backups. For details, see Protecting VMware virtual machines with file-level backups. |
Virtualized Active Directory servers |
To ensure database consistency, you must set up the virtualized Active Directory (AD) server in accordance with Microsoft best practices. If all Microsoft considerations are not addressed, backup and restore of the virtual machine may yield undesired results. If you prefer not to research these best practices, install the agent on the VM and protect it as you would a physical server (leveraging Microsoft’s VSS writers). |
Distributed File System environments |
Distributed File System (DFS) Namespaces and DFS Replication offer high-available access to geographically dispersed files. Because of the replication and syncing operations in DFS environments, you must set up the virtual machine in accordance with Microsoft best practices to ensure database consistency. If all Microsoft considerations are not addressed, backup and restore of the virtual machine may yield undesired results. If you prefer not to research these best practices, install the agent on the VM and protect it as you would a physical server (leveraging Microsoft’s VSS writers). |