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VMware HotAdd backups

For Unitrends Backup on VMware systems, it is recommended that you configure backups to use the HotAdd transport mode for ESX hosts whose datastores are located on an external SAN. This configuration enables vProtect to move data directly from the external SAN to the backup system 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 following topics to set up HotAdd backups:

ClosedVMware HotAdd requirements

In addition to the Virtualization Protector requirements, these requirements must be met to run VMware backups using the HotAdd transport mode:

• The Unitrends appliance must be a Unitrends Backup on VMware appliance running Unitrends version 7.1 or higher. (For Recovery Series appliances, use the SAN-direct feature instead. See VMware SAN-direct backups for details.)
• Both the Unitrends Backup VM and the VMs to protect must be running on a licensed ESXi 5.0 version or a higher licensed ESXi version listed in the Unitrends Compatibility and Interoperability Matrix, and must have one of the following storage configurations:
– SAN storage mounted on the ESX server as a VMFS data store.
– SAN storage mounted directly by the ESX guest as a virtual RDM disk.

Note:  ESXi 5.0 is no longer supported for new Unitrends Backup deployments.

• Both the Unitrends Backup system and the VM to back up must be added through a vCenter. Directly adding the Unitrends Backup or guest VM to the ESX host is not supported.
• The VMware vSphere version must either be version 5.0 or a higher version listed in the Unitrends Compatibility and Interoperability Matrix and must have an advanced license that supports the HotAdd feature. (See VMware documentation for details.)
ClosedAdditional HotAdd considerations

Consider the following before running backups using the HotAdd transport mode:

• The HotAdd transport mode can be used for all guest operating system versions.
• The HotAdd transport mode cannot be used to protect VMware templates.
• For optimal performance, it is recommended to use VAAI-compatible storage arrays with the HotAdd feature.

For non-VAAI storage arrays, the ESX host may perform certain operations on the datastore while the HotAdd backup is running, causing a SCSI reservation conflict. In this case, the backup will continue over the network instead of the SAN, which increases both backup time and network traffic on the LAN. To reduce the probability of reservation conflicts, follow VMware’s recommendations in the article Frequently Asked Questions for vStorage APIs for Array Integration (1021976).

ClosedTo configure a Unitrends Backup on VMware system for HotAdd backups

Note:  For Unitrends Backup on VMware systems, no configuration of the Unitrends storage subsystem is required. All configuration is done in the VMware and SAN environments.

1 Verify that the VMware HotAdd backups have been met.
2 Configure the ESX server(s) to access the datastore(s) on the SAN LUNS.
• In clustered environments, all ESX servers in the cluster must be configured to access the datastores.
• The following figure gives an exmple of how datastores should be configured for access by the Unitrends Backup on VMware system. In this example, the system can run a HotAdd backup of both VM1 and VM2 because the Unitrends Backup hypervisor is configured to access their datastores. However, VM3 cannot use the HotAdd method because the Unitrends Backup hypervisor cannot access its datastore.

3 Physically connect the ESX host machine to the SAN using an iSCSI or Fibre Channel cable.
4 Run backups for the desired guest VMs as described in Executing VMware backups.
• vProtect detects the SAN storage configuration and uses the SAN-direct transport method during backup.
• Note that when restoring SAN-direct backups, VMware determines the most efficient transport method. Data is usually restored directly to the ESX server as the VMFS data store must be utilized.

Important!   If vProtect cannot directly access the SAN, the backup runs using the network connection, moving the guest’s data from the external SAN through the ESX file system to the backup system. If using network bandwidth is a problem during certain hours, schedule your backups accordingly.

5 To check whether SAN-direct was used for a given backup, see To verify the HotAdd transport method was used.
ClosedTo verify the HotAdd transport method was used

If vProtect is unable to access the SAN directly, the backup runs using the regular network connection. Upon configuring the HotAdd feature and running the first backup, it is recommended that you verify that the HotAdd transport method was used.

To check whether the backup ran using the HotAdd transport method, double-click the backup in the Status window or on the Backups report to view associated details. Look for the following in the Raw Output in the vProtect Messages section:

• using transport method hotadd indicates the SAN connection was used for the backup.
• using transport method nbd or nsdssl the regular network connection was used for the backup. Check your physical cable connection and the iSCSI or FC configuration for issues.