Volume Clones
Never create a new VeraCrypt volume by cloning an existing VeraCrypt volume. Always use the VeraCrypt Volume Creation Wizard to create a new VeraCrypt volume. If you clone a volume and then start using both this volume and its clone in a way that both eventually contain different data, then you might aid cryptanalysis (both volumes will share a single key set). This is especially critical when the volume contains a hidden volume. Also note that plausible deniability (see section Plausible Deniability) is impossible in such cases. See also the chapter How to Back Up Securely.