Product : NetApp, NetApp HCI [HCI]/1.8 P1, x86
Feature : Data Locality, General, Storage Support
Content Owner:  Herman Rutten
NetApp HCI is based on a shared nothing storage architecture. NetApp HCI enables every drive in every storage node throughout the cluster to contribute to the storage performance and capacity of every volume presented by the Element software storage layer. When a VM is moved to another compute node, data remains in place and does not follow the VM because data is stored and available across all nodes residing in the cluster.

Whether data locality is a good or a bad thing has turned into a philosophical debate. Its true that data locality can prevent a lot of network traffic between nodes, because the data is physically located at the same node where the VM resides. However, in dynamic environments where VMs move to different hosts on a frequent basis, data locality in most cases require a lot of data to be copied between nodes in order to maintain the physical VM-data relationship. The SDS/HCI vendors today that choose not to use data locality, advocate that the additional network latency is negligible.