VMWare RAM and Storage Overhead Allocation

Owned by Keith Williams
12 Sept 2022
1 min read

Question:

Why does Cloud Director report more RAM and Storage for my VDC than the amount I ordered and is shown in MyAccount?

Answer:

Virtualisation has overheads for RAM and Storage for VMs. There is a RAM overhead for virtualisation components. Storage overhead includes an overhead for various virtualisation files that are not actual VM disk files as well as allowance for a RAM snapshot being written to disk.

When Zettagrid provisions VDCs we automatically provision extra RAM and Storage above what is ordered (and billed) to allow for these overheads so customers can utilise the full amount of storage and RAM they have ordered. It is not recommended for customers to allocate RAM or Storage beyond the ordered amount to their VMs. Errors may arise if there is not enough space for the virtualisation overhead.