6.0.1

n
Support of small les of 1KB.
n
Ability to open any le located on a VMFS5 datastore in a shared mode by a maximum of 32 hosts.
n
Scalability improvements on storage devices that support hardware acceleration. For information, see
Chapter 23, “Storage Hardware Acceleration,” on page 259.
n
Default use of ATS-only locking mechanisms on storage devices that support ATS. For information
about ATS-only locking and how to upgrade to ATS-only locking, see “VMFS Locking Mechanisms,” on
page 149.
n
Ability to reclaim physical storage space on thin provisioned storage devices. For information, see
“Array Thin Provisioning and VMFS Datastores,” on page 273.
n
Online upgrade process that upgrades existing datastores without disrupting hosts or virtual machines
that are currently running. For information, see “Upgrading VMFS Datastores,” on page 164.
For information about block size limitations of a VMFS datastore, see the VMware knowledge base article at
hp://kb.vmware.com/kb/1003565.
VMFS Datastores and Storage Disk Formats
Storage devices that your host supports can use either the master boot record (MBR) format or the GUID
partition table (GPT) format.
If you create a new VMFS5 datastore, the device is formaed with GPT. The GPT format enables you to
create datastores larger than 2TB and up to 64TB for a single extent.
VMFS3 datastores continue to use the MBR format for their storage devices. Consider the following items
when you work with VMFS3 datastores:
n
For VMFS3 datastores, the 2TB limit still applies, even when the storage device has a capacity of more
than 2TB. To be able to use the entire storage space, upgrade a VMFS3 datastore to VMFS5. Conversion
of the MBR format to GPT happens only after you expand the datastore to a size larger than 2TB.
n
When you upgrade a VMFS3 datastore to VMFS5, the datastore uses the MBR format. Conversion to
GPT happens only after you expand the datastore to a size larger than 2TB.
n
When you upgrade a VMFS3 datastore, remove from the storage device any partitions that ESXi does
not recognize, for example, partitions that use the EXT2 or EXT3 formats. Otherwise, the host cannot
format the device with GPT and the upgrade fails.
n
You cannot expand a VMFS3 datastore on devices that have the GPT partition format.
VMFS Datastores as Repositories
ESXi can format SCSI-based storage devices as VMFS datastores. VMFS datastores primarily serve as
repositories for virtual machines.
With VMFS5, you can have up to 256 VMFS datastores per host, with the maximum size of 64TB. The
required minimum size for a VMFS datastore is 1.3GB, however, the recommended minimum size is 2GB.
N 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 les, occupies a separate single directory. For the operating system inside the virtual machine, VMFS
preserves the internal le system semantics, which ensures correct application behavior and data integrity
for applications running in virtual machines.
Chapter 16 Working with Datastores
VMware, Inc. 147