A floppy disk is designed to rotate ___________ as compared to a hard disk drive.
1. faster
2.slower
3.at the same speed
4.None of the mentioned
A performance problem with _________ is the expense of computing and writing parity.
1.non-parity based RAID levels
2.parity based RAID levels
3.all RAID levels
4.None of the mentioned
A write of a block has to access ________
1. the disk on which the block is stored
2.parity disk
3.a parity block
4.All of the Mentioned
Defective sectors on disks are often known as ______
1.good blocks
2.destroyed blocks
3. bad blocks
4.None of the mentioned
In SCSI disks used in high end PCs, the controller maintains a list of _________ on the disk. The disk is initialized during ________ which sets aside spare sectors not visible to the operating system.
1.destroyed blocks, high level formatting
2.bad blocks, partitioning
3.bad blocks, low level formatting
4.destroyed blocks, partitioning
RAID level 3 supports a lower number of I/Os per second, because _______
1.Every disk has to participate in every I/O request
2.Only one disk participates per I/O request
3.I/O cycle consumes a lot of CPU time
4.All of the Mentioned
The data structure for a sector typically contains _______
1. header
2.data area
3. trailer
4.All of the Mentioned
A disk that has a boot partition is called a _________
1.start disk
2.end disk
3. boot disk
4.All of the Mentioned
A large number of disks in a system improves the rate at which data can be read or written if ______
1.the disks are operated on sequentially
2.the disks are operated on selectively
3. the disks are operated in parallel
4.All of the Mentioned
A single swap space ______ reside in two places.
1.can
2.cannot
3.must not
4.None of the mentioned
An unrecoverable error is known as ______
1.hard error
2.tough error
3.soft error
4.None of the mentioned
Consider a disk queue with requests for I/O to blocks on cylinders. 98 183 37 122 14 124 65 67 Considering FCFS (first cum first served) scheduling, the total number of head movements is, if the disk head is initially at 53 is?
1.600
2.620
3.630
4.640
Consider a disk queue with requests for I/O to blocks on cylinders. 98 183 37 122 14 124 65 67 Considering SSTF (shortest seek time first) scheduling, the total number of head movements is, if the disk head is initially at 53 is?
1.224
2.236
3.245
4.240
For most computers, the bootstrap is stored in ________
1. RAM
2.ROM
3. Cache
4.Tertiary storage
For swap space created in a separate disk partition where no file system or directory structure is placed, _____________ used to allocate and deallocate the blocks.
1. special routines must be
2.normal file system routines can be
3. normal file system routines cannot be
4.swap space storage manager is
If a disk fails in RAID level ___________ rebuilding lost data is easiest.
1.1
2.2
3.3
4.4
If a process needs I/O to or from a disk, and if the drive or controller is busy then ________
1.the request will be placed in the queue of pending requests for that drive
2.the request will not be processed and will be ignored completely
3. the request will be not be placed
4.None of the mentioned
If the mean time to failure of a single disk is 100,000 hours, then the mean time to failure of some disk in an array of 100 disks will be _________
1.100 hours
2.10 days
3. 10 hours
4.1000 hours
If the swap space is simply a large file, within the file system, ____ used to create it, name it and allocate its space.
1.special routines must be
2.normal file system routines can be
3. normal file system routines cannot be
4.swap space storage manager is
In RAID level 4, one block read, accesses _____
1.only one disk
2.all disks simultaneously
3.all disks sequentially
4.None of the mentioned
In SCSI disks used in high end PCs, the controller maintains a list of bad blocks on the disk. The disk is initialized during low-level formatting which sets aside spare sectors not visible to the operating system. The scheme used is known as _______ or _______
1.sector sparing & forwarding
2.forwarding & sector utilization
3.backwarding & forwarding
4.sector utilization & backwarding
In the ______ algorithm, the disk arm goes as far as the final request in each direction, then reverses direction immediately without going to the end of the disk.
1.LOOK
2.SCAN
3.C-SCAN
4.C-LOOK
In the ______ algorithm, the disk arm starts at one end of the disk and moves toward the other end, servicing requests till the other end of the disk. At the other end, the direction is reversed and servicing continues.
1.LOOK
2.SCAN
3. C-SCAN
4.C-LOOK
In the _______ algorithm, the disk head moves from one end to the other, servicing requests along the way. When the head reaches the other end, it immediately returns to the beginning of the disk without servicing any requests on the return trip.
1.LOOK
2.SCAN
3.C-SCAN
4.C-LOOK
In UNIX, two per process ________ are used by the kernel to track swap space use.
1.process tables
2.swap maps
3.memory maps
4.partition maps
It is __________ to reread a page from the file system than to write it to swap space and then to reread it from there.
1.useless
2.less efficient
3.more efficient
4.None of the mentioned
Linux __________ the use of multiple swap spaces.
1. allows
2.does not allow
3.may allow
4.None of the mentioned
Magnetic tape drives can write data at a speed ________ disk drives.
1.much lesser than
2.comparable to
3.much faster than
4.None of the mentioned
On media that use constant linear velocity (CLV), the _____________ is uniform.
1. density of bits on the disk
2.density of bits per sector
3. the density of bits per track
4.None of the mentioned
RAID level 0+1 is used because, RAID level 0 provides ______ whereas RAID level 1 provides ________
1.performance, redundancy
2.performance, reliability
3.redundancy, performance
4. none of the mentioned
RAID level 5 is also known as _______
1.bit-interleaved parity organization
2.block-interleaved parity organization
3.block-interleaved distributed parity
4.memory-style ECC organization
RAID level ____ spreads parity and data among all N+1 disks rather than storing data in N disks and parity in 1.
1.3
2.4
3.5
4.6
RAID level _____ is also known as block interleaved parity organisation and uses block level striping and keeps a parity block on a separate disk.
1.1
2.2
3.3
4.4
RAID stands for _______
1.Redundant Allocation of Inexpensive Disks
2. Redundant Array of Important Disks
3. Redundant Allocation of Independent Disks
4.Redundant Array of Independent Disks
Random access in magnetic tapes is _________ compared to magnetic disks.
1.fast
2.very fast
3.slow
4. very slow
SSTF algorithm, like SJF __________ of some requests.
1.may cause starvation
2. will cause starvation
3.does not cause starvation
4. causes aging
The header and trailer of a sector contain information used by the disk controller such as _________ and ____
1.main section & disk identifier
2.error correcting codes (ECC) & sector number
3.sector number & main section
4.disk identifier & sector number
The overall I/O rate in RAID level 4 is _______
1.low
2.very low
3.high
4.None of the mentioned
The potential overuse of a single parity disk is avoided in RAID level _______
1.3
2.4
3.5
4.All of the Mentioned
The process of dividing a disk into sectors that the disk controller can read and write, before a disk can store data is known as ________
1.partitioning
2.swap space creation
3.low-level formatting
4.None of the mentioned
The solution to the problem of reliability is the introduction of _______
1. aging
2.scheduling
3.redundancy
4.disks
The technique of duplicating every disk is known as _____
1.mirroring
2.shadowing
3.redundancy
4.All of the Mentioned
Using swap space significantly _________ system performance.
1.increases
2.decreases
3.maintains
4.does not affect
Virtual memory uses disk space as an extension of _____
1. secondary storage
2.main memory
3.tertiary storage
4.None of the mentioned
What is the disk bandwidth?
1.the total number of bytes transferred
2.total time between the first request for service and the completion on the last transfer
3. the total number of bytes transferred divided by the total time between the first request for service and the completion on the last transfer
4.None of the mentioned
What is the host controller?
1.controller built at the end of each disk
2.controller at the computer end of the bus
3.all of the mentioned
4. none of the mentioned
When a fixed amount of swap space is created during disk partitioning, more swap space can be added only by? I) repartitioning of the disk II) adding another swap space elsewhere
1.only I
2.only II
3.both I and II
4.Neither I nor II
When the head damages the magnetic surface, it is known as ________
1.disk crash
2.head crash
3. magnetic damage
4.All of the Mentioned
Where performance and reliability are both important, RAID level ____ is used.
1. 0
2.1
3.2
4. 0+1
_____ controller sends the command placed into it, via messages to the _____ controller.
1. host, host
2. disk, disk
3. host, disk
4.disk, host