This article outlines the transport methods available in vRanger Backup & Replication.
Machine & Virtual Appliance based Hot-Add transport method (Machine Hot-Add / VA Hot-Add):
Hot-add is a VMware feature which allows an administrator to add devices to a running Virtual Machine without having to power off the virtual machine. When running backups, this feature allows vRanger to attach the disks of the virtual machine we're backing up to a vRanger virtual appliance (vRanger VA) or to the vRanger server virtual machine in order to read data directly from the shared VMFS LUN.
Hot-add based backups do not put significant load on the production ESXi hosts.
Machine & Virtual Appliance based LAN (NBD/NBDSSL) transport method:
When no other transport method is available, vRanger can use LAN transport to access the virtual disks. Either NBD (Network block device) or NBDSSL (encrypted by SSL) can be used to read the disks and send the data to the vRanger server or the vRanger virtual appliance. This transport method is only used as a fallback transport method when no other advanced transport methods are available to process the backup.
As this transport method can put significant load on the production ESXi hosts, it is only recommended to use it as the fallback transport method.
Machine SAN and LAN-free transport method:
SAN mode requires that vRanger is installed on a physical server with access to the SAN storage (using Fibre Channel, iSCSI or SAS connections) that contains the VMware datastores/LUNs that contain the virtual disks to back up. The VMFS volumes containing the VM's to be protected must also be properly zoned or mapped to the vRanger server.
This is considered the most efficient method because it has direct access to the virtual disks and it doesn't put any load on the production ESXi hosts. If the vRanger physical server has direct access to the repository, LAN-free backups are possible.
