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.

Table 1. 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.

The following table compares major characteristics of VMFS5 and VMFS6. For additional information, see Configuration Maximums .

Table 2. Comparing 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:

  • 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.

  • 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.

  • 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.

  • Storage vMotion. Storage vMotion supports migration across VMFS, vSAN, and Virtual Volumes datastores. vCenter Server performs compatibility checks to validate Storage vMotion across different types of datastores.

  • 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.