6.5.1

Table Of Contents
Device Sector Formats and VMFS Versions
ESXi supports storage devices with traditional and advanced sector formats.
In storage, a sector is a subdivision of a track on a storage disk or device. Each sector stores a fixed
amount of data. Traditional 512n storage devices have been using a native 512-bytes sector size. In
addition, due to the increasing demand for larger capacities, the storage industry has introduced
advanced formats, such as 512-byte emulation, or 512e. 512e is the advanced format in which the
physical sector size is 4,096 bytes, but the logical sector size emulates 512-bytes sector size. Storage
devices that use the 512e format can support legacy applications and guest operating systems.
When you set up a datastore on a 512e storage device, VMFS6 is selected by default. For 512n storage
devices, the default option is VMFS5, but you can select VMFS6.
This table compares native 512-byte storage devices to the devices with the advanced 512e format.
Storage Device Format Logical Sector Size Physical Sector Size VMFS Datastore
512n 512 512 VMFS5 (default) and VMFS6
512e 512 4,096 VMFS6 (default) and VMFS5
Note Local 512e storage devices do
not support VMFS5.
Device Partition Formats and VMFS Version
Any new VMFS5 or VMFS6 datastore uses GUID partition table (GPT) to format the storage device. The
GPT format enables you to create datastores larger than 2 TB. If your VMFS5 datastore has been
previously upgraded from VMFS3, it continues to use the master boot record (MBR) partition format,
which is characteristic for VMFS3. Conversion to GPT happens only after you expand the datastore to a
size larger than 2 TB.
VMFS Datastores as Repositories
ESXi can format SCSI-based storage devices as VMFS datastores. VMFS datastores primarily serve as
repositories for virtual machines.
Note Always have only one VMFS datastore for each LUN.
You can store multiple virtual machines on the same VMFS datastore. Each virtual machine,
encapsulated in a set of files, occupies a separate single directory. For the operating system inside the
virtual machine, VMFS preserves the internal file system semantics, which ensures correct application
behavior and data integrity for applications running in virtual machines.
vSphere Storage
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