Computer Systems Quiz

What is a RAID 4?

• Many applications are dominated by small accesses

• Since the higher-level disk interfaces understand the health of a disk, it's easy to figure out which disk failed

• Also called mirroring or shadowing, there are two copies of every piece of data

At storage systems Gray and Siewiorek classify faults what does mean "Hardware faults"?

• Devices that fail, such as perhaps due to an alpha particle hitting a memory cell

• Faults in software (usually) and hardware design (occasionally)

• Mistakes by operations and maintenance personnel

At storage systems Gray and Siewiorek classify faults what does mean "Design faults"?

• Faults in software (usually) and hardware design (occasionally)

• Devices that fail, such as perhaps due to an alpha particle hitting a memory cell

• Mistakes by operations and maintenance personnel

At storage systems Gray and Siewiorek classify faults what does mean "Operation faults"?

• Mistakes by operations and maintenance personnel

• Devices that fail, such as perhaps due to an alpha particle hitting a memory cell

• Faults in software (usually) and hardware design (occasionally)

At storage systems Gray and Siewiorek classify faults what does mean "Environmental faults"?

• Fire, flood, earthquake, power failure, and sabotage

• Faults in software (usually) and hardware design (occasionally)

• Devices that fail, such as perhaps due to an alpha particle hitting a memory cell

If we talk about storage systems an interaction or transaction with a computer is divided for first what is an "Entry time" - ?

• The time for the user to enter the command

• The time between when the user enters the command and the complete response is displayed

• The time from the reception of the response until the user begins to enter the next command

If we talk about storage systems an interaction or transaction with a computer is divided for first what is an "System response time" - ?

• The time between when the user enters the command and the complete response is displayed

• The time for the user to enter the command

• The time from the reception of the response until the user begins to enter the next command

If we talk about storage systems an interaction or transaction with a computer is divided for first what is an "Think time" - ?

• The time from the reception of the response until the user begins to enter the next command

• The time for the user to enter the command

• The time between when the user enters the command and the complete response is displayed

Little's Law and a series of definitions lead to several useful equations for "Time server" -

• Average time per task in the queue

• Average time to service a task; average service rate is 1/Time server traditionally represented by the symbol μ in many queuing texts

• Average time/task in the system, or the response time, which is the sum of Time queue and Time server

Little's Law and a series of definitions lead to several useful equations for "Time queue" -

• Average time/task in the system, or the response time, which is the sum of Time queue and Time server

• Average time to service a task; average service rate is 1/Time server traditionally represented by the symbol μ in many queuing texts

• Average time per task in the queue