Dell Compellent Series 40 - Manual (Page 59)

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Glossary
A
Assigned Disks
Same as Managed Disks . Physical disks that are identified by Storage Center and to which
data can be written. Assigned disks use metadata to track information about volumes on
the disk and other assigned disks managed by the controller.
B
Back End
The component in the Storage Center SAN flow of data writes (server to switch to controller
to disks) that receive data writes. In general, drives in enclosures are the back end of the
controller. However, a remote system that is receiving replication data from a local Storage
Center is the back end local Storage Center.
Block Data
Raw data which does not have a file structure imposed on it. Database applications such
as a SQL Server or an Exchange Server transfer data in blocks. Block transfer is the most
efficient way to write to disk.
C
Cache
A high-speed memory or storage device used to reduce the effective time required to read
data from or write data to a lower speed memory or device. Storage Center provides cache
configuration to minimize disk latencies.
Clustered Controllers
More than one Storage Center controller that is interconnected at high-speeds to improve
reliability, availability, serviceability and performance via load balancing. Storage Center
provides automatic controller failover in an active-active configuration. Fully mirrored,
battery backup cache provides automatic restart. Volumes migrate between controllers in
the event of controller failure.