Click the user for which you would like to create an additional storage vault.

Click the option of your default storage vault. DO NOT click "Custom..."

If you would like to change the quota or name of the vault, Click the name of the vault you just created.

Click the "Name:" text field to change the name.

The default is Unlimited. If you would like to change that, uncheck "Unlimited" and change to the desired size.

Once you are finished making your changes, Click "Save"

How to create an additional Cloud Storage Vault