ESX storage refers to the storage space on a variety of physical storage systems, local or networked, that a host uses to store virtual machine disks.

A virtual machine uses a virtual hard disk to store its operating system, program files, and other data associated with its activities. A virtual disk is a large physical file, or a set of files, that can be copied, moved, archived, and backed up as easily as any other file. To store virtual disk files and manipulate the files, a host requires dedicated storage space.

The host uses storage space on a variety of physical storage systems, including your host’s internal and external devices, or networked storage, dedicated to the specific tasks of storing and protecting data.

The host can discover storage devices to which it has access and format them as datastores. The datastore is a special logical container, analogous to a file system, where ESX places virtual disk files and other files that encapsulate essential components of a virtual machine. Deployed on different storage devices, the datastores hide specifics of each storage device and provide a uniform model for storing virtual machine files.

Using the vSphere Client, you can set up datastores on any storage device that your host discovers. In addition, you can use folders to create logical groups of datastores for organizational purposes, and for setting permissions and alarms across the datastore group.