Product : Scale Computing, HC3 [HCI]/8.6.5, x86
Feature : Data Locality, General, Storage Support
Content Owner:  Herman Rutten
Scale Computing HC3 is based on a shared nothing storage architecture. Scale Computing HC3 enables every drive in every node throughout the cluster to contribute to the storage performance and capacity of every virtual disk (VDS) presented by the SCRIBE storage layer. When a VM is moved to another 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 requires 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.