This refers to PowerFlex File (formerly PowerFlex NAS).

While the core PowerFlex product is a block storage solution (providing raw LUNs/Volumes which cannot be safely shared by two standard OS hosts without a cluster file system like VMFS or OCFS2), PowerFlex File introduces NAS nodes. These nodes format the block storage and present it via NFS or SMB protocols. These protocols are specifically designed to allow multiple clients to read and write to the same file system concurrently, enabling true data sharing across the network.