About the vSAN Default Storage Policy

vSAN requires that the virtual machines deployed on the vSAN datastores are assigned at least one storage policy. When provisioning a virtual machine, if you do not explicitly assign a storage policy to the virtual machine the vSAN Default Storage Policy is assigned to the virtual machine.

The default policy contains vSAN rule sets and a set of basic storage capabilities, typically used for the placement of virtual machines deployed on vSAN datastores.

Table 1. vSAN Default Storage Policy Specifications

Specification	Setting
Failures to tolerate	1
Number of disk stripes per object	1
Flash read cache reservation, or flash capacity used for the read cache	0
Object space reservation	0 Note: Setting the Object space reservation to zero means that the virtual disk is thin provisioned, by default.
Force provisioning	No

You can review the configuration settings for the default virtual machine storage policy when you navigate to the VM Storage Policies > vSAN Default Storage Policy > Manage > Rule-Set 1: VSAN.

For best results, consider creating and using your own VM storage policies, even if the requirements of the policy are same as those defined in the default storage policy. In some cases, when you scale up a cluster, you must modify the default storage policy to maintain compliance with the requirements of the Service Level Agreement for VMware Cloud on AWS.

When you assign a user-defined storage policy to a datastore, vSAN applies the settings for the user-defined policy on the specified datastore. At any point, you can assign only one virtual machine storage policy as the default policy to the vSAN datastore.

Characteristics

The following characteristics apply to the vSAN Default Storage Policy.

• The vSAN default storage policy is assigned to all virtual machine objects if you do not assign any other vSAN policy when you provision a virtual machine. The VM Storage Policy text box is set to Datastore default on the Select Storage page. For more information about using storage policies, see the vSphere Storage documentation.
  Note: VM swap and VM memory objects receive the vSAN Default Storage Policy with Force provisioning set to Yes.
• The vSAN default policy only applies to vSAN datastores. You cannot apply the default storage policy to non-vSAN datastores, such as NFS or a VMFS datastore.
• Because the default virtual machine storage policy is compatible with any vSAN datastore in the vCenter Server, you can move your virtual machine objects provisioned with the default policy to any vSAN datastore in the vCenter Server.
• You can clone the default policy and use it as a template to create a user-defined storage policy.
• You can edit the default policy, if you have the StorageProfile.View privilege. You must have at least one vSAN enabled cluster that contains at least one host. Typically you do not edit the settings of the default storage policy.
• You cannot edit the name and description of the default policy, or the vSAN storage provider specification. All other parameters including the policy rules are editable.
• You cannot delete the default policy.
• The default storage policy is assigned when the policy that you assign during virtual machine provisioning does not include rules specific to vSAN.