Data ONTAP provides the ability to clone FlexVol volumes, creating FlexClone volumes. The following list outlines some key facts about FlexClone volumes that you should know:
FlexClone volumes are a point-in-time, writable copy of the parent volume. Changes made to the parent volume after the FlexClone is created are not reflected in the FlexClone.
FlexClone volumes are fully functional volumes; you manage them on the Manage Volumes page, just as you do the parent volume.
FlexClone volumes always exist in the same aggregate as their parent volumes.
FlexClone volumes can themselves be cloned.
FlexClone volumes and their parent volumes share the same disk space for any data common to the FlexClone and parent. This means that creating a FlexClone is instantaneous and requires no additional disk space (until changes are made to the FlexClone or parent).
Because creating a FlexClone does not involve copying data, FlexClone creation is very fast.
FlexClone volumes are created with the same space guarantees as their parent.
Note: In Data ONTAP 7.0, space guarantees were disabled for FlexClone volumes. In Date ONTAP 7.1 and above, space guarantees are enabled when FlexClone volumes are created.
While a FlexClone exists, some operations on its parent volume are not allowed:
You cannot delete the base snapshot of a parent volume while a cloned volume exists. The base snapshot is the snapshot that was used to create the FlexClone. It is named clone_clonename.x, where clonename is the name of the FlexClone and x is a numeral that distinguishes it from other snapshots.
You cannot perform a volume SnapRestore operation on the parent volume using a snapshot that was taken before the base snapshot was taken.
You cannot destroy a parent volume if any FlexClone of that volume exists.
You cannot clone a volume that has been taken offline or is restricted, although you can restrict the parent volume or take it offline after it has been cloned.
You cannot use either the parent volume or the FlexClone as a destination for a copied volume or volume SnapMirror.
If, at a later time, you decide you want to sever the connection between the parent and the FlexClone, you can split the FlexClone. This removes all restrictions on the parent volume.
Note: Splitting a FlexClone from its parent volume deletes all existing snapshots of the FlexClone.
When a FlexClone is created, quotas are reset on the FlexClone, and any LUNs present in the parent volume are present in the FlexClone but are unmapped. For more information about using volume cloning with LUNs, see the Data ONTAP Block Access Management Guide.
Only FlexVol volumes can be cloned. To create a copy of a traditional volume, you must go to the command line and use the vol copy command, which creates a distinct copy with its own storage.
You must install the license for the FlexClone feature before you can create FlexClone volumes.