One scenario is when a new policy that requires a change in component number and or layout is assigned to a vm.
Vsan storage policy change.
Transient capacity is generated when vsan reconfigures objects for a policy change.
Prerequisites verify that the vm storage policy you want to assign as the default policy to the vsan datastore meets the requirements of virtual machines in the vsan cluster.
You can change the default storage policy for a selected virtual volumes or vsan datastore.
Another scenario is when an existing storage policy that is assigned to one or more vms is modified.
How vsan manages policy changes.
For virtual volumes and vsan datastores vmware provides storage policies that are used as the default during the virtual machine provisioning.
Create a new policy go to vm storage policies.
Virtual san fails to provision a virtual machine when the policy requirements are not met but it successfully creates the user defined storage policy.
The policy is editable.
The vsan default policy only applies to vsan datastores.
Because the managed storage policy for non elastic vsan clusters varies based on cluster size adding or removing hosts will trigger a storage policy reconfiguration if it changes the size of the cluster so that it requires a different policy.
Click the virtual machine whose policy you want to modify.
On the vm storage policies tab click the storage policy you want to change.
From the vsphere web client home click policies and profiles vm storage policies.
You can change the default storage policy for a selected vsan datastore.
Now the question remains how do i change the policy of a single vm.
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.
When you modify a policy the change is accepted but not applied immediately.
When editing the policy you cannot change the name of the policy or the vsan storage provider specification.
If you configure the object space reservation then reservation will be done on the vsan datastore for the specified object or the vm on which this policy is assigned.
In both cases vsan will use additional capacity to make the necessary changes to components to comply with the assigned storage policy.
Click the vms tab and click virtual machines.
It is actually really straight forward.
To edit the policy you must have the storage policy privileges that include the view and update privileges.
Vsan 6 7 update 3 and later manages policy changes to reduce the amount of transient space consumed across the cluster.
In the vsphere web client.
You can see the list of virtual machines that use this storage policy.
