Risposta multipla Flashcards
Which sentence about Tier Level 4 of datacenter is not correct?
A All cooling equipment is independently dual-powered
B Single non-redundant distribution path serving the IT equipment
C Meets or exceeds all Tier 3 requirements
D Fault-tolerant site infrastructure with availability of 99.995%
B
In the context of data centers, scalability is the ability for the infrastructure __________
without cost, efficiency, and reliability being compromised. Select the correct item to be included
in the previous sentence.
A to be enlarged or to handle an increment of the input requests
B to run in a larger building
C none of the others
D to improve the cooling strategy
A
Which is the most appropriate definition for “fault”?
A Any library inconsistency in the Operating System
B Any defect in the silicon caused by dust particles during manufacturing
C Any inappropriate usage of the system
D Any event interfering with the nominal behavior of the system
D
Which of these levels is NOT part of a typical three-layers network architecture of a data-center?
A Access
B Aggregation
C Core
D Cloud
D
Question 1
Which is the main characteristic of the D-Cell topology for data center network architectures?
A The network is organized in a distributed way
B The network comprises edge, aggregation and core layers
C the network is organized in a recursive way
D the network is organized in a hierarchical way
C
Which of the following is not a feature of a fat tree topology in a data center network architecture?
A It has multiple connections to the core
B None of the others
C It has a recursive organization
D It has a three-tier model
C
What is the Hardware-level virtualization?
A The virtualization layer is placed between the operating system and the applications
B The virtualization layer is above the applications
C The virtualization layer is placed between the hardware and the operating system
D The virtualization layer is placed below the hardware
C
Which aspect is a drawback of data center computing platform?
A Power consumption
B Device independence
C Universal access
D Unlimited storage capacity
A
In the context of SSDs, one of the following activities is NOT managed by the Flash Translation
Layer:
A Defragmentation
B Address Translation
C Garbage Collection
D Data Allocation
A
A System VM:
A Provides the interface to system ISA and user ISA
B Provides the interface to system ABI and the user ISA
C Provides the interface to system ABI and the user ABI
D Provides the interface to system calls and user ABI
A
Consider an array of N disks. Select the right order of the RAID levels in terms of effective data
storage in ascending order, i.e. for the lower to the higher data storage availability.
A RAID 1+0, RAID 6, RAID 5
B RAID 6, RAID 5, RAID 1+0
C None of the others
D RAID 1+0, RAID 5, RAID 6
A
One of these configurations is not considered in Data-center network architectures. Which one?
A D-Cell
B Three layers
C Fat-tree
D Direct Connections
D
What is the average latency for an Hard Disk Drive?
A Time to wait for the sector
B Time to wait for the data transfer
C Time to wait for the head movement
D Time to wait for the cylinder
A
What is the TBW in a Solid State Disk?
A Total amount of data that must be written into an SSD before the completion of the space
B Total amount of data that can be written into an SSD before it is likely to fail
C Total amount of data that can be read from an SSD
D Total amount of data that can be written into an SSD
B
The following sentence: “The probability that the component does not fail in the interval 0 … t,
knowing that at the instant t = 0 the component was working correctly” defines:
A Dependability
B Reliability
C Availability
D None of the other
B
Consider an array of N disks. Select the right order of the RAID levels in terms of MTTFRAID
in descending order, i.e. for the higher to the lower MTTF. Consider a number of disks N that is
large enough to satisfy the minimum requirements for all the RAID levels.
A None of the others
B RAID 5, RAID 1+0, RAID 0+1
C RAID 1+0, RAID 0+1, RAID 5
D RAID 0+1, RAID 5, RAID 1+0
C
To increase reliability, which of the following actions is not correct?
A Have spare components at disposal
B Reduce MTTR to a minimum
C Use elements with low MTTF
D Use multiple redundant components
C
What is a Network Attached Storage (NAS)?
A a computer connected to a network that provides computation to other devices
B a remote storage unit connected to PC using a specific networking technology
C a storage system directly attached to a server or workstation
D a computer connected to a network that provides only file-based data storage services to
D
Select the wrong definition. A Virtual Machine:
A none of the others
B may appear as having different resources than the physical machine
C may result in a different level of performance with respect to the physical machine
D provides identical software behavior
A
What are the benefits of data center virtualization?
A All of the other answers listed are correct.
B Consolidation and ease of manageability.
C Cost savings in power and cooling of the data center.
D Flexibility and agility
A
Which statement about Paravirtualization is correct?
A It cannot be used with traditional Operating Systems
B Hooks are not required
C Guest OS and VMM are independent each other
D It is the same of Kernel-level Virtualization
A
When dependability-related requirements must be considered? Select the right answer.
A Only during requirements definition
B When starting testing/verification activities
C When a prototype of the system is available
D In every phase of the design flow
D
A System Virtual Machine can provide its functionality:
A Only on the hardware
B Only on top of an Operating System
C Either working directly on the hardware or running on an Operating System
D None of the others
C
In a three-layer network architecture of a Datacenter, which is the layer that is
typically associated to the TOR switch?
A Access
B Core
C Aggregation
D None of the others
A
