Datastores are logical containers, analogous to file systems, that hide specifics of each storage device and provide a uniform model for storing virtual machine files. Datastores can also be used for storing ISO images, virtual machine templates, and floppy images.

You use the vSphere Client to access different types of storage devices that your ESX host discovers and to deploy datastores on them.

Depending on the type of storage you use, datastores can be backed by the following file system formats:

Virtual Machine File System (VMFS)

High-performance file system optimized for storing virtual machines. Your host can deploy a VMFS datastore on any SCSI-based local or networked storage device, including Fibre Channel and iSCSI SAN equipment.

As an alternative to using the VMFS datastore, your virtual machine can have direct access to raw devices and use a mapping file (RDM) as a proxy.

Network File System (NFS)

File system on a NAS storage device. ESX supports NFS version 3 over TCP/IP. The host can access a designated NFS volume located on an NFS server, mount the volume, and use it for any storage needs.

If you use the service console to access your ESX host, you can see the VMFS and NFS datastores as separate subdirectories in the /vmfs/volumes directory.