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:
How Storage Virtualization Works
User Interface for Storage Center Management
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.
Disk Management Sorts disks into disk folders and assigns a storage type based on the disk types.
Volumes Allocate storage for use.
Storage Types Define a datapage size and redundancy levels for the disk folder.
Data Progression Moves pages between tiers and drive types, as well as among multiple RAID levels within the same tier.
Storage Profiles Define how data progression moves pages between tiers.
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.
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36 Storage Center Overview