Dell Storage Manager 2020 R1 Administrator's Guide

Controllers

A Storage Center controller provides the central processing capability for the Storage Center Operating System and managing RAID storage. A Storage Center is typically configured with a pair of controllers. In a dual-controller Storage Center configuration, the two controllers must be the same model.

I/O cards in the controller provide communication with disk enclosures and servers that use the storage. Controllers provide two types of I/O ports:

• Front-end ports – Hosts, servers, or Network Attached Storage (NAS) appliances access storage by connecting to controller Fibre Channel I/O cards, FCoE I/O cards, or iSCSI I/O through one or more network switches. Some storage systems contain SAS ports that are designated as front-end ports, which can be connected directly to a server. Ports for front-end connections are located on the back of the controller, but are configured as front-end ports.
• Back-end ports – Enclosures, which hold the physical drives that provide back-end storage, connect directly to the controller. Fibre Channel and SAS transports are supported through ports designated as back-end ports. Back-end ports are in their own private network between the controllers and the drive enclosures.