Virtual Disk Transport Methods

VMware supports file-based or image-level backups of virtual machines hosted on an ESXi host with SAN or NAS storage. Virtual machines read data directly from a shared VMFS LUN, so backups are efficient and do not put significant load on production ESXi hosts or the virtual network.

VMware offers interfaces for integration of storage-aware applications, including backup, with efficient access to storage clusters. Developers can use VDDK advanced transports, which provide efficient I/O methods to maximize backup performance. VMware supports four access methods: local file, NBD (network block device) over LAN, NBD with SSL encryption (NBDSSL), SAN, and SCSI HotAdd.