Administrator Guide
3
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).
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 dening volumes and mapping them to servers. The Storage Type and Storage Prole
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: Dene 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 Proles: Denes how data progression moves pages between tiers.
Storage Center Hardware Components
Dell Storage Center consists of one or two controllers, switches, and may 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 can be congured with a single controller or a pair of controllers. In a dual-controller Storage Center
conguration, the two controllers must be the same model.
IO cards in the controller provide communication with disk enclosures and servers that use the storage. Controllers provide two
types of IO ports:
• Front-end ports: Hosts, servers, or Network Attached Storage (NAS) appliances access storage by connecting to controller
Fibre Channel IO cards, FCoE IO cards, or iSCSI IO through one or more network switches. SAS ports, designated as front-end
ports, can be connected directly to a server on SCv2000 series storage systems. Ports for these connections are located on the
back of the controller, but are congured 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 IO 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 IO 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.
Storage Center Overview
59