Dell Compellent Series 40 - Manual (Page 433)

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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.
Asynchronous Replication
After data has been written to the primary storage site, new writes to that site can be accepted without
having to wait for the secondary (remote) storage site to also finish its writes. Asynchronous Replication
does not have the latency impact that synchronous replication does, but if the primary site failed before the
data was written to the secondary site the data that had not yet been written could be lost. See also
replication.
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, disk 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. See
Target System .
Backup
A two step process. A Replay is first copied to a non-volatile disk remote system. In the event of problems
(such as disk drive failures, power outages, or virus infection) resulting in data loss or damage to the original
data, the Replay is retrieved and restored to a View Volume.
Bandwidth
The amount of data that can be sent to or from Storage Center per internal time.
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.