VMware ESXi and vSphere Cluster Management

What Is a Datastore in VMware vSphere?

Learn what a VMware vSphere datastore is, where it resides, what it stores, and how to view details and browse files in vCenter.

A datastore is a logical storage container used by VMware vSphere to hold files for virtual infrastructure. It gives ESXi hosts and vCenter Server a consistent way to work with storage without requiring administrators to manage every device-specific detail through the virtual machine interface.

A datastore is not the same thing as a physical disk, a storage array, a logical unit number (LUN), a storage area network (SAN), or an NFS share. Those are storage resources or access methods beneath the datastore. The datastore is the storage location that vSphere presents for virtual machine files and other administrator-managed content.

In practical terms, an ESXi host consumes storage from a local disk, SAN, or NAS system, and vSphere presents that storage as a datastore. Virtual machines then use files in the datastore for their virtual disks, configuration data, and related content.

For a concise definition, see What Is a Datastore.

How the Datastore Abstraction Works

Storage can be complex underneath the virtualization layer. A physical disk may be installed in an ESXi server, a SAN may present shared block storage, or a NAS appliance may export a file share through NFS. Each option has different hardware, protocols, and management tools.

The datastore provides a common vSphere storage location above those details. ESXi can place virtual machine files in the datastore, while vCenter can display the datastore in inventory and provide operations for inspecting its capacity, properties, and files.

  • Physical storage: The disk, storage array, or NAS appliance that supplies capacity.
  • Storage access method: A local disk connection, SAN block-storage path, or NFS network connection.
  • File-system model: Usually VMFS for block storage or the NAS provider's file system for NFS storage.
  • Datastore: The vSphere storage container visible to ESXi and vCenter.
  • Virtual machine files: The files stored inside the datastore and used to run or manage VMs.

Where Datastores Can Be Located

Local datastores

A local datastore is backed by a disk or disks attached directly to an ESXi server. For example, an ESXi host might use an internal disk to create a datastore for a test virtual machine.

Local storage is associated with the host that owns or accesses the attached disk. It is therefore not automatically available to every ESXi host in a cluster. This makes local datastores useful for host-specific workloads, test environments, or situations where shared storage is not required.

SAN-backed datastores

A storage area network (SAN) provides block storage to servers over a dedicated storage network. A SAN can present storage to one or more ESXi hosts, commonly as a logical block device such as a LUN.

When the storage design supports shared access, multiple ESXi hosts can use a datastore on the SAN. For block storage datastores, vSphere commonly uses VMFS as the file system. Shared VMFS storage is important for cluster features and for allowing hosts to access the same virtual machine files, subject to the design and feature requirements of the environment.

NAS and NFS datastores

Network-attached storage (NAS) provides file-based storage over a network. ESXi can mount an export from a NAS appliance using the Network File System (NFS) protocol and present that mounted storage as an NFS datastore.

An NFS datastore does not format the NAS share with VMFS. Instead, the NAS system supplies and manages the underlying file system. vSphere uses the NFS-mounted location as a datastore while the storage provider remains responsible for the file-system implementation beneath it.

Storage Sources and File-System Models

Storage source | Typical access method | Datastore file-system model | Example use

Local server disk | Direct attachment to an ESXi host | VMFS for block storage | A test VM stored on an internal host disk

SAN-backed block storage | Block-storage paths from a SAN, often through a presented LUN | VMFS, such as VMFS5 | Shared storage accessed by several ESXi hosts

NAS/NFS storage | NFS mount from a NAS appliance | The file system supplied by the NAS provider | A network file share presented as an NFS datastore

What Datastores Store

Datastores hold the files that make up or support virtual machines. They can also contain reusable images and ordinary files uploaded by administrators.

Virtual machine files

Virtual machine files include virtual disks and VM configuration-related files. A virtual disk contains the guest operating system, applications, and data visible to the VM. Configuration-related files describe the virtual machine and help the virtualization platform operate it.

These files are often grouped in a folder named after the virtual machine. The exact set of files depends on the VM's configuration and current operations, such as snapshots or virtual disk activity.

Templates

A template is a reusable virtual machine image. Administrators can use a template as a starting point for deploying consistent VMs. Template content is stored on a datastore so vSphere can access it when creating or deploying virtual machines.

ISO images

An ISO image is a disk-image file. Administrators commonly store ISO files on a datastore and attach them to a VM's virtual CD/DVD drive to install an operating system or perform configuration and recovery tasks.

Other files

Administrators may also upload, move, or remove other files through the datastore browser. Examples include installation media, scripts, exports, and temporary files. File operations should be planned carefully, especially when a file might be referenced by a VM or another vSphere operation.

Common Datastore Content

Content type | Purpose | Typical administrator action

Virtual machine files | Store VM virtual disks and configuration-related data | Create, power on, migrate, back up, or manage the VM through vSphere rather than casually editing its files

Templates | Provide reusable VM images for deployment | Deploy new VMs or update the template through an approved workflow

ISO images | Provide installation or configuration media | Upload the ISO and attach it to a VM virtual CD/DVD drive

VMFS and NFS Datastores

VMFS means Virtual Machine File System. It is VMware's clustered file system for block-storage datastores. VMFS is designed for vSphere environments in which ESXi hosts may need to access a shared datastore, provided that the storage presentation and configuration support that access.

VMFS5 is an example of a VMFS datastore version that may appear in a vSphere environment. The file-system type and version are useful details when reviewing datastore inventory and planning compatibility or administration tasks.

An NFS datastore follows a different model. NFS is a file-sharing protocol, and the NAS provider supplies the file system on the exported storage. ESXi mounts the export and uses it as a datastore; it does not create a VMFS file system on that share.

  • Block storage from a local disk or SAN commonly uses VMFS.
  • File storage from a NAS system commonly uses NFS and the provider's native file system.
  • Both can appear as datastores in vSphere.
  • The datastore abstraction does not mean every datastore is a VMFS volume.

Viewing Datastores in vCenter

vCenter Server is the centralized management platform used to view and manage vSphere inventory. The vSphere Web Client is the management interface context in which administrators inspect datastores and browse their files.

The exact labels can vary between vSphere versions, but the conceptual navigation is:

  1. Sign in to the vCenter or vSphere Web Client.
  2. Open the inventory or storage view.
  3. Select the Datastores section.
  4. Review the datastore inventory list.

The datastore inventory view provides an overview of available datastores in the selected vCenter context. Useful details include the datastore name, accessibility, capacity and free space, associated hosts, and file-system type. For example, an administrator might see two datastores and identify both as VMFS5.

vCenter / vSphere Web Client
  > Inventory or Storage view
    > Datastores
      > Select a datastore
        > Review details or browse files

Viewing Datastore Details

To inspect one datastore, select or open it from the datastore inventory. Its details view provides information about the storage characteristics and the way vSphere sees the datastore.

Depending on the vSphere version and permissions, details may include the datastore's file-system type, capacity, available space, host associations, storage backing, and configuration status. Use this view to confirm that you selected the intended datastore before performing file or storage operations.

Browsing and Managing Datastore Files

The datastore browser is the vSphere interface for viewing files and folders stored on a datastore. From the datastore inventory, select the datastore, open its actions or context menu, and choose Browse Files when that option is available.

In the browser, an administrator can inspect folders and file names and may be able to perform actions such as:

  • Upload an ISO image or another approved file.
  • Move a file to another folder on the datastore.
  • Delete an obsolete file after confirming that it is not in use.
  • Review a VM folder and identify virtual disks and configuration-related files.

Practical Examples

Local ESXi storage

An ESXi host uses an internal disk to create a local datastore. A test virtual machine's virtual disk and configuration-related files are placed there. The datastore is available to that host, but other hosts should not be assumed to have access to it.

Shared SAN storage

Several ESXi hosts access storage presented by a SAN. The block storage is formatted as a VMFS datastore, allowing the shared storage location to appear in the virtual infrastructure. The hosts can access the same datastore when the SAN presentation and vSphere configuration are correct.

NFS-backed storage

An administrator mounts an NFS export from a NAS appliance as a datastore. The NAS supplies the underlying file system, while vSphere presents the mounted location as an NFS datastore. VM files and ISO images can be stored there according to the environment's policies.

Datastore contents

A datastore contains a virtual machine folder, a reusable VM template, and an ISO image used to install a guest operating system. The datastore browser allows the administrator to inspect these items, while normal vSphere workflows manage the VM and template relationships.

Troubleshooting Datastore Questions

A datastore is not visible in the vCenter inventory

  • Verify that the relevant storage has been presented or mounted for the intended ESXi host.
  • Determine whether the expected storage is local, SAN-backed, or NFS-backed.
  • Check the selected host, cluster, and vCenter context. A local datastore should not be assumed to be shared.
  • For SAN storage, verify that the intended hosts can see the block storage and that the datastore is mounted as designed.
  • For NFS storage, verify the NAS export, network reachability, and mount configuration.

An ISO or VM-related file cannot be found

  • Open the correct datastore in the datastore browser rather than looking only at the datastore inventory list.
  • Review folders and file names carefully; an ISO may be in a shared media folder, while VM files are often in a VM-specific folder.
  • Confirm that the VM is using the datastore you opened.
  • Remember the distinction between the datastore inventory view and the files stored inside that datastore.

A required VM file was moved or deleted

  • Stop further file changes until the VM's dependencies and current tasks are understood.
  • Verify the file's ownership and relationship to the affected VM, including virtual disks and snapshot-related files.
  • Check available backups or recovery procedures before attempting an alteration.
  • Use datastore browser operations cautiously, particularly for VM folders and virtual disk files.

One datastore shows VMFS and another shows NFS

This difference normally reflects the storage source and access model. VMFS is associated with block storage such as local disks or SAN-presented storage. NFS datastores use file storage exported by a NAS system and retain the provider's file-system model. Both are datastores, but a datastore is not necessarily a VMFS volume.

Exam-Relevant Notes

  • A datastore is a logical vSphere storage container, not the same as the physical storage beneath it.
  • ESXi hosts consume datastore storage, and vCenter Server provides centralized inventory and management views.
  • Local datastores are backed by disks attached to an ESXi host.
  • SANs commonly provide shared block storage, which commonly uses VMFS.
  • VMFS is VMware's clustered file system for block-storage datastores; VMFS5 is an example of a VMFS version.
  • NFS datastores are mounted from NAS storage and use the file system supplied by the NAS provider rather than VMFS.
  • Datastores can contain VM files, templates, ISO images, and other administrator-managed files.
  • The datastore browser is used to inspect and manage files, but direct changes to VM-related files can disrupt virtual machines.