During transfer operations, View Transfer Server reduces the amount of data that must be sent over the network by taking advantage of guest file system optimization.

When a desktop virtual machine contains a primary NTFS partition, View Transfer Server transfers the blocks that are allocated by NTFS. Unallocated blocks are not transferred. This strategy minimizes the total number of blocks to be transferred.

Guest file system optimization occurs only when data is transferred from primary NTFS partitions. View Transfer Server does not perform this optimization on extended partitions, Logical Disk Manager partitions, or compressed NTFS volumes on Windows 7 or Windows Vista virtual machines.

Guest file system optimization differs from data deduplication and compression, which also optimize data transfers but are independent of the desktop's guest operating system. For details about these operations, see Optimizing Data Transfers Between Local-Desktop Host Computers and the Datacenter.