• Prerequisites: A primary storage is not overprovisioned or uses the thick provisioning. This primary storage must be ImageStore.
  • Example: Assume that you create a VM instance (A) that occupies 400 G by using a 800 G primary storage. Encapsulate A as an image (B). The actual size for B is less than 400 G. Presumably, B only holds 10 G. Then, use B to create a new VM instance (C). Now, B will be downloaded from a backup storage to the cache directory of this primary storage. 10 G of this primary storage will be consumed. After download, the virtually available capacity for this primary storage holds only 390 G. However, creating C requires the 400 G capacity. Hence, C fails to be created.