You can create a virtual hard disk and add it to a virtual machine.


Select a virtual machine.

In the virtual machines and templates inventory tree, select a group of virtual machines and select a virtual machine from the list on the right.

Search for a virtual machine and select it from the search results list.


In the VM Hardware panel, click Edit Settings.


Click Virtual Hardware.


From the Add a device drop-down menu, select New Hard Disk and click Add device.

The hard disk appears in the virtual devices list.


Click the triangle next to the new hard disk to expand the hard disk options.


(Optional) Type a value in the Provisioned Size text box and select the units from the drop-down menu.


Select the location for the virtual disk.



Store the disk with the virtual machine

Select Store with the virtual machine.

The disk will be stored in the same location as the virtual machine configuration file.

Store the disk on another datastore or datastore cluster


Select Browse.


Select a datastore or datastore cluster.


If you selected a datastore cluster and do not want to use Storage DRS with this disk, select Disable Storage DRS for this virtual machine and select a datastore within the datastore cluster.


Click OK.


Select a disk provisioning option.



Allocate and commit space on demand (Thin Provisioning)

Saves storage space. For the thin disk, you provision as much datastore space as the disk would require based on the value you enter for the disk size. However, the thin disk starts small and at first, uses only as much datastore space as the disk actually needs for its initial operations.


If a virtual disk supports clustering solutions such as Fault Tolerance, do not make the disk thin.

If the thin disk needs more space later, it can expand to its maximum capacity and occupy the entire datastore space provisioned to it. Also, you can manually convert the thin disk into a thick virtual disk.

Flat pre-initialized

A type of thick virtual disk that support clustering features such as Fault Tolerance. Space required for the virtual disk is allocated at creation time. In contrast to the flat format, the data remaining on the physical device is overwritten with zeroes during creation. It might take much longer to create disks in this format than to create other types of disks.


In the Shares drop-down menu, select a value for the shares to allocate to the virtual disk.

Shares is a value that represents the relative metric for controlling disk bandwidth. The values Low, Normal, High, and Custom are compared to the sum of all shares of all virtual machines on the host. Share allocation symbolic values can be used to configure their conversion into numeric values.


If you selected Custom, type a number of shares in the text box.


In the Limit - IOPs box, enter the upper limit of storage resources to allocate to the virtual machine, or select Unlimited.

This value is the upper limit of I/O operations per second allocated to the virtual disk.


Accept the default or select a different virtual device node.

In most cases, you can accept the default device node. For a hard disk, a nondefault device node is useful to control the boot order or to have different SCSI controller types. For example, you might want to boot from an LSI Logic controller and share a data disk with another virtual machine that is using a Buslogic controller with bus sharing turned on.


(Optional) Select a disk mode.




Dependent disks are included in snapshots.

Independent - Persistent

Disks in persistent mode behave like conventional disks on your physical computer. All data written to a disk in persistent mode are written permanently to the disk.

Independent - Nonpersistent

Changes to disks in nonpersistent mode are discarded when you power off or reset the virtual machine. With nonpersistent mode, you can restart the virtual machine with a virtual disk in the same state every time. Changes to the disk are written to and read from a redo log file that is deleted when you power off or reset.


Click OK.