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VMware virtual machines

This section provides considerations and requirements for protecting VMware environments.

Preparing for VMware backups

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 ESX hosts directly or through a vCenter server. You can add ESX hosts, vCenter servers, or both to the Unitrends appliance to protect your VMs. For some features (described in Additional VMware requirements), a vCenter is required.

Following is a summary of the high-level steps that protect VMware virtual machines. Included are links to detailed instructions for each procedure.

1 Review the VMware virtual machines.
2 Add the VMware host to your Unitrends appliance. See Adding a virtual host.
3 Create backup jobs for your VMs. See Creating backup copy jobs.

Best practices and requirements for VMware protection

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

VMware host best practices and considerations
VMware virtual machine best practices and considerations
General VMware requirements
Additional VMware requirements

VMware host best practices and considerations

The following VMware servers can be added to the Unitrends appliance to protect hosted virtual machines:

Item

Description

vCenter and associated ESX servers

If ESX servers belong to a vCenter and both are accessible on the network, Unitrends recommends that you add the vCenter and its ESX servers to the appliance. This enables the appliance to contact the vCenter for management operations (including vMotion support) and to directly contact the ESX servers for backup and recovery, potentially improving performance by reducing network traffic around the vCenter server.

vCenter only

If the ESX servers are accessible through a vCenter, adding the vCenter to the Unitrends appliance automatically detects all of the associated ESX 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 ESX servers. In this case, the appliance detects when VMs move between ESX servers in a cluster and contacts the appropriate server to perform backups.

ESX server only

If ESX servers are not accessible through a vCenter, or if only a subset of the VMs hosted on the vCenter’s ESX servers are to be protected, you can add indvidual ESX servers. In this case, the appliance contacts the ESX servers directly for backup and recovery.

VMware virtual machine best practices and considerations

Follow these best practices to protect your VMware virtual machines:

Adhere to VMware's best practices.
If you are adding an ESX 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 ESX 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 General VMware requirements for details.
In some cases, you may want or need to protect VMs by using asset-level backups. For recommendations, see Protecting VMware virtual machines at the asset level.
Do not run host-level backups for VMs that you are protecting at the asset level. Doing so can compromise log truncation changes for applications and lead to other undesirable results.
To protect hosted Exchange or SQL simple recovery model applications, use the application-aware feature for host-level backups. See Application-aware protection for details.
If recovery time objectives are very important, set up VMware instant recovery to quickly spin up a failed VM from host-level backups.
For virtual disks hosted on an NFS 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 KB 1167.
Host-level protection is not supported for the following (use asset-level backups instead):
VMs in a cluster configuration with a fault tolerant disk.
VMs with dynamic MAC addresses.
Independent and pass-though 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 hosted on Free ESXi versions.

General VMware requirements

The following requirements must be met for host-level protection of VMware virtual machines.

Item

Description

ESX host

Must be a licensed version listed in the Unitrends Compatibility and Interoperability Matrix.

Note:  Additional requirements and limitations apply to ESXi 6. See Additional VMware requirements for details.

vCenter

Must be a licensed version listed in the Unitrends Compatibility and Interoperability Matrix.

Note:  Additional requirements and limitations apply to vCenter 6. See Additional VMware requirements for details.

vCenter or ESX 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 ESX server to the backup appliance.

Virtual machine configuration

Verify the following VM configuration settings:

VM hardware version must be 4, 7, 8, 9,10, or 11.
VMware tools must be installed in the guest operating system to ensure file system and application consistency.

Note:  On Vsphere 5.5. VMware introduced new SATA Virtual Hardware Controllers with vSphere 5.5 and VM Hardware Version 10. See KB 1500 for details on selecting the correct controller when creating new VMs in version 5.5.

Change Block Tracking (CBT)

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.

Note:  On hardware version 4. Only full backups are supported for VMs configured with hardware version 4.

Additional VMware requirements

These additional requirements may apply to your environment.

Item

Description

vSphere 6

To protect hosted VMs in vCenter 6 or ESXi 6 environments, these additional requirements and limitations apply:

The Unitrends appliance must be running release 8.2 or higher. (Unitrends version 8.1 supports basic vSphere 6 functionality only. To use features introduced in vSphere 6, and to use the SAN-direct and HotAdd transport modes, you must be running 8.2 or higher).
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 ESX 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 appliances

For ESX 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 the Unitrends Knowledge Base for requirements and setup procedures.

HotAdd backup for UEB on VMware appliances

For ESX 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 the Unitrends Knowledge Base for requirements and setup procedures.

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).