Data that is already present before adding a node is not rebalanced across all nodes within a Federation. This is in accordance with HPE SimpliVity 2600s data locality strategy. However, data is automatically rebalanced across all nodes before removing/evicting a node from a Federation.
Data can be rebalanced at any time, but currently requires a HPE SimpliVity 2600 Support engagement. Some customers have regular, support-initiated cadences for rebalancing.