LAN Free Backup for SAN-Based Storage
LAN free backup is used automatically when:
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Virtual machines to be backed up are on SAN datastores.
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Each proxy that performs backup operations is a physical server.
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The Virtual Server Agent (VSA) and MediaAgent are both deployed on each proxy.
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Each MediaAgent has local access to directly connected storage using a shared mount path.
During backup, the VSA reads the virtual machine disks (VMDKs) directly over the SAN, performs block level deduplication, and sends the data to a local MediaAgent that writes to the shared library. SAN transport mode provides the fastest method for full or incremental backups because data is not sent over the LAN. Data is never transferred over the IP network, except when the library is configured on a network-attached storage (NAS) device.
Physical Proxy Installations
In a physical proxy configuration, the Virtual Server Agent and MediaAgent are installed on a physical server with visibility into the storage network. A purely physical implementation performs SAN-only backups and usually provides the best performance.
When to Use
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Datastores are configured on Fibre Channel (FC) or iSCSI SAN.
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Physical server has SAN access to datastore LUNs.
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Direct tape copies are required or physical MediaAgents are required for secondary operations.
When Not to Use
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SAN access to datastore LUNs is only available within the ESX Server environment.
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SAN transport is not available for storage accessed using the Network File System (NFS) protocol.