Dell Compellent Series 30 - Manual (Page 437)

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Fibre Channel
A high-speed interconnect used to connect servers to Storage Center controllers and back-end disk
enclosures. FC components include HBAs, hubs, switches, and cabling. The term FC also refers to a high-
speed, fully duplexed serial communication protocol permitting data transfer rates of up to 10 Gigabit per
second.
Front End
The component in the Storage Center SAN flow of data writes (server to switch to controller to disks) that
initiates data writes. In general, servers (or switches) are the front end of the controller. However, a Storage
Center system that is replicating data to a remote system is the front end of the remote system. See
Back
End .
G
GUI
Graphical User Interface
H
HBA
By convention, Storage Center refers to the ports on cards in server as HBAs.
HBA Type
In the Storage Center, there are two HBA types: FC and iSCSI.
High Availability
A continuously available system is characterized as having essentially no downtime in any given year. A
system with 99.999% availability experiences only about five minutes of downtime. In contrast, a high
availability system is defined as having 99.9% uptime, which translates into a few hours of planned or
unplanned downtime per year.
HBA (Host Bus Adapter)
The HBA is the intelligent hardware residing on the host server that controls the transfer of data between
the host and the Storage Center.
HNR
Host Name Resolution
HTTP
Hyper Text Transfer Protocol
Hot Spare
A hot spare disk is a backup disk. In the event that an active array fails, the controller makes the hot spare
part of the active array and rebuilds data on the fly. Although the hot spare becomes an active disk without
human intervention, remember to replace the failed drive as soon as possible, so that the array is again
protected with a new hot spare. Hot spares can span multiple disk enclosures. A Storage Center hot spares
can have a different capacity than the data drive it replaces.