User guide

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• Distributed parity. Parity (error correction code) data is distributed
across several drives in RAID 5, RAID 6, and RAID 50 configurations.
Distributing parity data across drives provides both protection of data
and
good performance.
• Drive ID. A unique identifier for a specific drive in a system. Also called a
port ID.
•
Drive Number. The SCSI number, or channel number, of a particular
drive.
•
ECC. Error correction code. ECC Errors are grown defects that have
occurred on a drive since it was last read.
•
ECC Error policy. Determines whether an error detected during a rebuild
stops the rebuild or whether the rebuild can continue in spite of the error.
Specified by the Continue on Source Error During Rebuild unit policy.
•
EMS (Enclosure Management Services). Chassis-monitoring functions
for environmental, power, mechanical monitoring, and control using the
I²C (chassis control) bus port.
•
Export a unit. To remove the association of a unit with a controller. Does
not affect the data on the drives. Used for array roaming, when you want
to swap out a unit without powering down the system, and move the unit
to another controller. Compare to Delete, which erases all unit
configuration information from the drive.
•
Exportable unit or drive. In 3BM (BIOS), exportable units and drives
are those that will be available to the operating system when you boot
your computer.
•
Fault tolerant. A RAID unit which provides the ability to recover from a
failed drive, either because the data is duplicated (as when drives are
mirrored) or because of error checking (as in a RAID 5 unit).
•
Firmware. Computer programming instructions that are stored in a read-
only memory on the controller rather than being implemented through
software.
•
Grown defect. Defects that arise on a disk from daily use.
•
Hot spare. A drive that is available, online, and designated as a spare.
When a drive fails in a redundant unit, causing the unit to become
degraded, a hot spare can replace the failed drive automatically and the
unit will be rebuilt.
•
Hot swapping. The process of removing a disk drive from the system
while the power is on. Hot swapping can be used to remove units with
data on them, when they are installed in hot-swap carriers. Hot swapping
can also be used to remove and replaced failed drives when a hot-swap
carrier is used.