VMwares clustered file system, allowing for concurrent access of multiple hosts for live migration, file based locking (to ensure data consistency), dynamic volume resizing etc.
new in VMFS 6
Support for 4K Native Drives in 512e mode
SE Sparse Default
Automatic Space Reclamation
Support for 512 devices and 2000 paths (versus 256 and 1024 in the previous versions)
CBRC aka View Storage Accelerator