Which actions are initiated when a snapshot is created on an XtremIO array?

When a copy is created, the volume's existing metadata becomes an "ancestor" entity (parent object) that is shared between the production volume and the copy. New empty containers are created for subsequent changes to both the production volume and the virtual copy volume. Therefore, the act of creating a copy is instantaneous and involves no data or metadata copies.

References: https://www.emc.com/collateral/white-paper/h13035-wp-introduction-to-xtremio-snapshots.pdf, pages 18