VMFS5 vs VMFS6

Several versions of the VMFS file system have been released since its introduction. ESXi supports VMFS3, VMFS5, and VMFS6.

For all VMFS version, ESXi offers complete read and write support. On all versions of VMFS, you can create and power on virtual machines.

Host Access to VMFS Versions:-

VMFS	ESXi
VMFS6	Read and write
VMFS5	Read and write
VMFS3	Read and write Note: You can continue to use existing VMFS3 datastores, but you cannot create new ones. If you have existing VMFS3 datastores, migrate virtual machines to the VMFS6 datastore.

Comparison of VMFS5 and VMFS6

Features and Functionalities	VMFS5	VMFS6
Access for ESXi 6.5 hosts	Yes	Yes
Access for ESXi hosts version 6.0 and earlier	Yes	No
Datastores per host	512	512
512n storage devices	Yes (default)	Yes
512e storage devices	Yes. Not supported on local 512e devices.	Yes (default)
Automatic space reclamation	No	Yes
Manual space reclamation through the esxcli command. See Manually Reclaim Accumulated Storage Space.	Yes	Yes
Space reclamation from guest OS	Limited	Yes
GPT storage device partitioning	Yes	Yes
MBR storage device partitioning	Yes For a VMFS5 datastore that has been previously upgraded from VMFS3.	No
Storage devices greater than 2 TB for each VMFS extent	Yes	Yes
Support for virtual machines with large capacity virtual disks, or disks greater than 2 TB	Yes	Yes
Support of small files of 1 KB	Yes	Yes
Default use of ATS-only locking mechanisms on storage devices that support ATS. See VMFS Locking Mechanisms.	Yes	Yes
Block size	Standard 1 MB	Standard 1 MB
Default snapshots	VMFSsparse for virtual disks smaller than 2 TB. SEsparse for virtual disks larger than 2 TB.	SEsparse
Virtual disk emulation type	512n	512n
vMotion	Yes	Yes
Storage vMotion across different datastore types	Yes	Yes
High Availability and Fault Tolerance	Yes	Yes
DRS and Storage DRS	Yes	Yes
RDM	Yes	Yes

 
When you work with VMFS5 and VMFS6 datastores, consider the following:

1. Upgrade. After you upgrade your ESXi hosts to version 6.5, you can continue using any existing VMFS5 datastores. To take advantage of VMFS6 features, create a VMFS6 datastore and migrate virtual machines from the VMFS5 datastore to VMFS6 datastore. You cannot upgrade the VMFS5 datastore to VMFS6.
2. Datastore Extents. A spanned VMFS datastore must use only homogeneous storage devices, either 512n or 512e. The spanned datastore cannot extend over devices of different formats.
3. Block Size. The block size on a VMFS datastore defines the maximum file size and the amount of space a file occupies. VMFS5 and VMFS6 datastores support the block size of 1 MB.
4. Storage vMotion. Storage vMotion supports migration across VMFS, vSAN, and Virtual Volumes datastores. vCenter Serverperforms compatibility checks to validate Storage vMotion across different types of datastores.
5. Storage DRS. VMFS5 and VMFS6 can coexist in the same datastore cluster. However, all datastores in the cluster must use homogeneous storage devices, either 512n or 512e. Do not mix devices of different formats within the same datastore cluster.