With ESXi, you can use two models of thin provisioning, array-level and virtual-disk level thin provisioning.

Thin provisioning is a method that optimizes storage utilization by allocating storage space in a flexible on-demand manner. Thin provisioning contrasts with the traditional model, called thick provisioning. With thick provisioning, a large amount of storage space is provided in advance in anticipation of future storage needs. However, the space might remain unused causing underutilization of storage capacity.

The VMware thin provisioning features help you eliminate storage underutilization problems at the datastore and storage array level.

Create Thin Provisioned Virtual Disks in the VMware Host Client

To save storage space, you can create thin provisioned virtual disks. The thin provisioned virtual disk starts small and grows as more disk space is required. You can create thin disks only on the datastores that support disk-level thin provisioning.

The following procedure assumes that you are creating a new virtual machine. For more information, see Create a Virtual Machine in the VMware Host Client.

Procedure

  1. Right-click Host in the VMware Host Client inventory and select Create/Register VM.
    The New Virtual Machine wizard opens.
  2. Select a method for adding a new virtual machine on the host and click Next.
  3. Enter a name for your virtual machine.
  4. Select the virtual machine compatibility from the Compatibility drop-down menu.
  5. Select a guest operating system version from the Guest OS version drop-down menu and click Next.
  6. From the list of accessible datastores on the Select storage page of the New Virtual Machine wizard, select the destination datastore for the virtual machine configuration files and all of the virtual disks.
  7. On the Virtual Hardware tab, expand Hard disk.
  8. Under Disk Provisioning, select the Thin provisioned radio button and click Next.
  9. On the Ready to complete page of the New Virtual Machine wizard, review the configuration settings for the virtual machine and click Finish to save your settings.

View Virtual Machine Storage Resources in the VMware Host Client

You can view how datastore storage space is allocated for your virtual machines in the VMware Host Client.

Resource Consumption shows how much datastore space is occupied by virtual machine files, including configuration files, log files, snapshots, virtual disks, and so on. When the virtual machine is running, the used storage space also includes swap files.

For virtual machines with thin disks, the actual storage usage value might be less than the size of the virtual disk.

Procedure

  1. Click the virtual machine in the VMware Host Client inventory.
  2. Review the Resource Consumption information in the lower right area of the virtual machine summary page.

Determine the Disk Format of a Virtual Machine in VMware Host Client

You can determine whether your virtual disk is provisioned in thick or thin format.

Procedure

  1. Right-click the virtual machine in the VMware Host Client inventory and select Edit settings.
  2. On the Virtual Hardware tab, expand Hard disk.
    The Type text box shows the format of your virtual disk.