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Array- Multiple disks that function as one
independent disk
ATA- "AT Attachment" which is a hard drive with
an integrated controller
Cache- A temporary storage area for frequently
used data
Cold Swap- When the power must be turned off
before removing or adding a component to the system
Controller- A module that controls signals
between the host and peripheral device (ex: an adapter
card)
Disk Failure Detection- When the RAID controller
automatically detects SCSI drive failure
Disk Traveling- Occurs when drives are placed in
a different order than the original order
Drive Groups- A group of drives logically linked
together and acting as one unit
Duplexing- Mirroring across two RAID cards
ECC- "Error Correcting Code" which is generating
redundant information used to detect and correct data
errors
External RAID Controller- A RAID controller which
functions externally
Fault Tolerance- The capability of the system to
continue functioning when one component fails
Host- Any system to which drives are attached and
used for input/output operations and the storage of data
Hot Spare- A drive (which does not belong to the
system) which can be used by the controller to rebuild a
critical system drive
Hot Swap- Ability to replace a bad drive with a
good drive without interrupting the server processing
and activities
Interface- A hardware or software protocol that
allows for the hard disk and the computer to exchange
data (ex: SCSI or ATA)
Internal RAID Controller- A controller circuit
board on a server or typically on the bus of the
computer
JBOD- "Just a Bunch of Disks" which can appear to
be a RAID array but actually are not and function
independently
Mirrored Hard Drive- Two drives containing the
same information so if one drive fails the other drive
functions in its place
Mirroring- Duplication of data on one drive to
another at the same time each time the computer writes
data
Parity- Used by RAID 5 to spread parity bits
across each of the disks to enable the recreation of
data if a drive fails
Parity Check- The controller verifies the
integrity of the data on the system drive and corrects
any inconsistencies
Partitioning- The appearance of several "images"
whose capacity of each image totals that of the entire
array
RAID- "Redundant Array of Independent or
Inexpensive Disks"
RAID Data Recovery- The process of recovering and
rebuilding the data from a failed RAID array
RAID Level- One of many different possible
configurations of a RAID array
RAID 0- Striping at the block level occurs across
multiple drives with no redundancy
RAID 1- Pairing and mirroring occurs and the data
is 100% duplicated
RAID 3- Striping occurs across several drives and
is written in parallel with parity information stored on
one drive
RAID 5- Striping not in parallel occurs across
multiple drives and parity information is spread among
all the drives
RAID 10- A combination of RAID 0 striping and
RAID 1 mirroring providing the security of data
redundancy
SCSI- "Small Computer System Interface" which
allows different devices to be connected to a PC using a
SCSI card
Spanning- The ability to configure multiple drive
packs allowing the volume to be larger than a single
drive
Stripe Order- The order in which the drives
appear in an array- this is crucial to rebuild the
failed drives
Stripe Size- The size in kilobytes of a single
input/output operation in the array
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