Administrator Guide

Table Of Contents
Storage Center Overview
Storage Center is a storage area network (SAN) that provides centralized, block-level storage that can be accessed by Fibre
Channel, iSCSI, or Serial Attached SCSI (SAS).
Topics:
Storage Center Hardware Components
How Storage Virtualization Works
User Interface for Storage Center Management
Storage Center Hardware Components
Storage Center consists of one or two controllers, switches, and might include one or more disk enclosures.
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.
Switches
Switches provide robust connectivity to servers, allowing for the use of multiple controllers and redundant transport paths.
Cabling between controller I/O cards, switches, and servers is referred to as front-end connectivity.
Enclosures
Enclosures house and control drives that provide storage. Enclosures are connected directly to controller I/O cards. These
connections are referred to as back-end connectivity.
Fibre Channel Switched Bunch of Disks (SBOD) and Serial Advanced Technology Attachment (SATA) enclosures are supported
for existing Storage Centers and for controller migrations only.
How Storage Virtualization Works
Storage Center virtualizes storage by grouping disks into pools of storage called Storage Types, which hold small chunks
(pages) of data. Block-level storage is allocated for use by defining volumes and mapping them to servers. The storage type and
storage profile associated with the volume determines how a volume uses storage.
Storage Center combines the following features to provide virtualized storage.
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