PowerFlex fundamentally consists of three types of software components that make up the PowerFlex software: the Storage Data Server (SDS), the Storage Data Client (SDC), and the Meta Data manager (MDM). Version 3.5 introduces a new component that enables replication—the Storage Data Replicator (SDR).
The SDS is a software element that runs on PowerFlex nodes that contribute media to a storage cluster in a PowerFlex infrastructure. It allows PowerFlex to aggregate the media while sharing these resources as one or more unified pool on which logical volumes are created.
The SDC allows an operating system or hypervisor to access data served by PowerFlex clusters. The SDC is a client-side software component that can run natively on Windows, Linux, IBM AIX, ESXi, and other operating systems.
MDMs control the behavior of the PowerFlex system. They determine and publish the mapping between clients and their data, keep track of the state of the system, and issue reconstruct directives to SDS components. MDMs maintain a state of “quorum” in PowerFlex, ensuring that a minimum number of nodes are always available to maintain infrastructure availability.
In the VMware environment, the MDM, and SDS components are installed on SVM, whereas the SDC is installed directly on the ESX host. The SVMs dedicated to PowerFlex OS provide clustering and storage services.