Chapter 18 Flashcards
Availability
The long-term average of time
that a system is in service and is
satisfactorily performing its
intended function.
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Data Center
A building or portion of a
building whose primary function
is to house a computer room
and its support systems.
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HDA
Horizontal Distribution Area
A space in a computer room where a horizontal cross-connect HC is
located and may include LAN switches, storage area network (SAN) switches, and keyboard/video/mouse (KVM) switches for the end equipment located in the equipment distribution areas.
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Information Security
The practice of protecting the
confidentiality, integrity, and
availability of data
and resources.
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MDA
Main Distribution Area
The space in an equipment
room where the main cross-
connect is located.
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“N”
Need
Symbol used to represent “the
need” for redundancy in a
particular system.
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Reliability
The probability that a given
system will operate properly
without failure for a
given period of time.
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Redundancy
Providing secondary
components that either become
instantly operational or are
continuously operational so that
the failure of a primary
component will not result in
mission failure.
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Name 2 advantages of
redundancy in a
data center.
1.lncreases fault tolerance
2.Increases maintainability
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Name 2 negative
consequences of adding
redundant components in
case of failures.
- Reduces efficiency
2.Increases losses
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What is an N-Base
A data center redundancy level
indicating that the system meets
base requirements and has
no redundancy
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What is N+1 redundancy?
A data center redundancy level
that provides one additional unit,
module, path, or system in
addition to the minimum
required to satisfy the
base requirement
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What is N+2 redundancy?
A data center redundancy level
that provides two additional
units, modules, paths, or
systems in addition to the
minimum required to satisfy
the base requirement
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What is 2N redundancy?
A data center redundancy level
that provides two complete
units, modules, paths, or
systems for each one required
for a base system
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What is 2(N+1)
redundancy?
A data center redundancy level
that provides two complete
(N+1) units, modules, paths,
or systems
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A data center has an N+l
redundancy level. Will
performing maintenance
on two units disrupt
operations?
Yes, an N+l redundancy level
allows for maintenance of a
single unit without disruption.
Therefore, performing
maintenance on two unit will
disrupt the system.
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A data center has an N+2
redundancy level. Will the
failure of two modules
disrupt operations?
No, an N+2 redundancy level will
provide enough protection to
prevent disruption of operations.
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A data center has a 2N
redundancy level. Will the
failure of an entire unit
disrupt operations?
No, a 2N redundancy level will
provide enough protection to
prevent disruption of operations.
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A data center has an N-
Base requirement. Will the
failure of one path
disrupt operations?
Yes, the N-Base requirement
means that the system has no
redundancy, and the failure of
one path will disrupt operations.
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Name 4 areas of concern
that are used to define
data center facility
availability classes.
1 .Component redundancy
2.System redundancy
3.Quality control
4.Survivability
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How does component
redundancy increase
reliability?
By providing redundancy for
critical high-risk, low-reliability
components within systems
TDMM.* Page 18-5