Both volume migration and external replication support ONTAP FlexGroups as source volumes.
A FlexGroups volume is a large volume internally built out of multiple FlexVols, known as member volumes or constituents. NetApp Volumes uses FlexGroups internally to provide its large capacity volumes or large volume feature.
When replicating a FlexGroup volume to NetApp Volumes, the
destination volume must also be a large volume. The number of constituents on
the destination large volume must match with the number of constituents on the
source FlexGroup. As external replication can't read this number from the source
volume, you must specify it during replication creation using the
large-volume-constituent-count parameter within the
hybrid-replication-parameters parameter block.
The large-volume-constituent-count you provide must meet the following
criteria:
It must be between 2 and 36.
No odd numbers are allowed, with the exceptions of 3 and 5.
If your source FlexGroup's constituent count doesn't meet these requirements, you must change the source FlexGroup constituent count to a correct value before establishing an external replication. Once the replication is enabled, you can't change the constituent count on NetApp Volumes. Therefore, don't add constituents to an ONTAP FlexGroup that is already in replication with NetApp Volumes.
External replications between FlexGroups and large volumes don't support the
EVERY_10_MINUTES replication schedule. However, volume migration uses a fixed
HOURLY replication schedule.