Quest vRanger Architecture Options for Backing up vSphere 5 Environments

Data movement, or the transferring of protected virtual machine data from the host to the backup destination, is the most important aspect of your VMware vSphere 5 data protection architecture. Knowing your deployment and configuration options (architecture options) is a crucial planning step in order to optimize the performance of your vRanger backups.

vRanger Support and Integration with vSphere 5

vRanger is VMware Ready™ certified for vSphere 5, which means it has undergone and passed rigorous testing by VMware to ensure compatibility and support for vSphere 5. This significant investment is crucial to enable vRanger to provide a continuous, standardized data protection process as you upgrade to vSphere 5, and continue to virtualize more of your production environment.

LAN-Free Backup

Installing vRanger on a physical machine with either a fibre channel or iSCSI SAN connected host environment provides maximum scalability and performance for backing up vSphere 5 environments. In this configuration, vRanger can perform LAN-free backups by invoking VMware’s SAN transport mode. LAN-free backup can be utilized as the primary backup method, while network backup can be employed for fail-safe redundancy in the event LAN-free fails.

The benefits of this configuration include:

  • Leveraging your existing investment in SAN
  • Isolating backup and restore traffic to the fibre channel or iSCSI network, completely offloading your production hosts and network from data protection overhead and traffic
  • Enabling extremely high performance and scalability for data protection operations
    • Adding HBAs or NICs to the backup machine (one dedicated to reading and another to writing) further increases performance and scalability

This configuration is illustrated below. Here, vRanger acts as a physical proxy server with storage connections to VMFS and the backup repository. The vRanger machine must be attached to fibre channel or iSCSI SAN environment, and the VMFS volumes containing the protected virtual machines must also be presented to the vRanger machine. vRanger initiates the virtual machine snapshot and reads the VMDKs directly from the fibre SAN or iSCSI LUN that stores the virtual disks. The backup data traffic flows through the vRanger server, and then is written to the repository.

Figure 1: LAN-Free Backup

The steps in LAN-free backup mode can be further broken down as follows:

  1. vRanger retrieves the job configuration from the database
  2. vRanger establishes a connection to the repository
  3. vRanger adds a temporary snapshot to the protected virtual machine
  4. vRanger mounts the protected VMDKs to the vRanger physical machine, using vStorage API’s proxy mount and SAN advanced transport mode
  5. vRanger reads from the source disk, and transfers data from the protected host to the repository
  6. vRanger deletes the temporary snapshot on the protected virtual machine

There are a number of factors to consider in this configuration, including the number of virtual machines protected by each vRanger physical proxy server. As a starting point, we recommend using one proxy server for every 10 hosts or every 100 virtual machines.

Coinciding with the number of protected virtual machines is the number of virtual machines that can be processed concurrently. The number of concurrent tasks running locally can be set between one through 20 via the Options menu, with the default set to three. As a starting point, we recommend one task per CPU core. If your server has eight cores, for example, start with the maximum number of tasks running locally set to eight.

Note that scalability will also depend on the amount of memory on the vRanger machine and network bandwidth available to write to repositories.

Be sure to disable automount on the vRanger machine so that Windows does not assign drive letters to protected VMDKs when they’re mounted to the vRanger machine. Do not initialize or format unknown or offline disks from the vRanger machine – these represent your VMFS volumes and any changes could potentially corrupt the VMFS volumes.

LAN-Free / Hot Add Backup

vRanger must be installed in a virtual machine to leverage Hot Add transport. The Hot Add transport mode involves a SCSI Hot Add on the host where vRanger is running. LAN-free / Hot Add backup works with SAN or local storage, without using the LAN. You can use vRanger’s LAN-free / Hot Add backup as the primary method, and utilize network backup as a secondary mode for redundancy.

The benefits of this configuration include:

  • Simple to deploy and configure
  • vRanger is deployed in a virtual machine
  • vRanger read speeds are extremely fast as they occur at native virtual machine performance

In this configuration, illustrated below, vRanger is provided with direct access to protected VMDKs through vSphere’s I/O stack rather than through the network. The vRanger server in this configuration acts as a proxy server, since the VMDKs are temporarily mounted directly to the vRanger virtual machine, and all backup data traffic flows through the vRanger virtual machine to shared or local storage.

Figure 2: LAN-Free / Hot Add Backup

The steps in the LAN-free / Hot Add backup mode can be further broken down as follows:

  1. vRanger retrieves the job configuration from the database
  2. vRanger establishes a connection to the repository
  3. vRanger adds a temporary snapshot to the protected virtual machine
  4. vRanger mounts the protected VMDKs to the vRanger virtual machine, using vStorage API’s Hot Add advanced transport mode
  5. vRanger reads from the source disk, and transfers data from the protected host to the repository
  6. vRanger deletes the temporary snapshot on the protected virtual machine

In order to employ Hot Add, the vRanger virtual machine must be able to access the datastores for all protected virtual machines. Make sure the protected virtual disks on the datastore have block sizes that match the block sizes for the vRanger virtual machine datastore. Hot Add only works for backing up virtual machines with iSCSI disks, and not IDE disks.

If the vRanger virtual machine can be vMotioned, all hosts that it can be vMotioned to must be able to see the storage for all protected virtual machines as well. Also, be sure to disable automount on the vRanger virtual machine so that Windows does not assign drive letters to protected VMDKs when they’re mounted to the vRanger virtual machine.


vRanger can process a significant amount of data to the repository very quickly provided it has enough available resources. As a guideline, allow for two concurrent jobs per vCPU. We recommend configuring the vRanger virtual machine with a minimum of four vCPUs – one for the vRanger server and three for job activities, which allows for up to six concurrent jobs. If you need to run a higher number of concurrent jobs, simply add additional vCPUs.

We also recommend adding a second SCSI controller to the vRanger virtual machine so that it can mount more protected disks at the same time during the Hot Add operation. vRanger can mount as many virtual disks as vSphere allows.

Network Backup

In network backup, vRanger backs up virtual machines via each host over the LAN utilizing either VMware’s LAN or Hot Add transport method.

The benefits of network backup include:

  • It’s vRanger’s default configuration so it’s the easiest to configure, it works out of the box
  • vRanger can be deployed in a virtual or physical machine

This configuration is illustrated below. When vRanger is installed in a virtual machine it can leverage VMware’s Hot Add transport mode, provided the proper conditions are met for Hot Add. In this case the VMDKs of the protected virtual machines will be mounted to the vRanger virtual machine. This provides vRanger with direct access to protected data, so reading occurs at native virtual machine speeds, meaning it’s very fast. When vRanger is installed on a physical machine, network backup will leverage VMware’s LAN transport mode.

Figure 3: ESXi Network Backup

When vRanger is installed in a virtual machine, the steps included in network backup mode include:

  1. vRanger retrieves the job configuration from the database
  2. vRanger establishes a connection to the repository
  3. vRanger adds a temporary snapshot to the protected virtual machine
  4. vRanger mounts the protected VMDKs to the vRanger virtual machine, using vStorage API’s Hot Add advanced transport mode
  5. vRanger reads from the source disk, and transfers data from the protected host to the repository
  6. vRanger deletes the temporary snapshot on the protected virtual machine

When vRanger is installed on a physical machine, the backup data is sent to the vRanger server and onto the repository after the snapshot is taken.

Network backup mode can be utilized for redundancy when vRanger is installed on a physical machine with fibre channel or iSCSI SAN connected hosts. When a LAN-free backup fails, vRanger can failover the transport mode to network based backup so that the job will complete, although it will take longer to process. To ensure backup data traffic does not flow over the network at any time, you can disable the option to perform a network backup on LAN-free failure, in which case, the backup job will fail upon LAN-free backup failure.

Performance may vary when running vRanger backups over the production network, depending on the total traffic during job activity, and available resources and network bandwidth. Best practice is to separate vRanger data traffic from the production network by configuring a dedicated backup network through a second management NIC.

Flexible Architecture Options for Backup

As you can see, vRanger provides a high degree of flexibility in terms of architecture options for backup, to help you obtain the best performance for your specific environment.

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