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lmms-lab
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CSBench_MCQ

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1.43k
⌀
1,820
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The correct statement about storage management is ().
The purpose of storage protection is to restrict the allocation of memory.
In a time-sharing system with memory M and N users, each user occupies M/N of the memory space.
In a virtual memory system, as long as the disk space is unlimited, a job can have an arbitrarily large addressing space.
To implement virtual memory management, corresponding hardware support is required.
D
null
1,821
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Among the following memory management schemes, the () method can adopt static relocation.
Fixed Partition
Variable Partitioning
Paging
Segmental
A
null
1,822
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
A storage management that does not produce internal fragmentation is ().
Paged Memory Management
Segmented Memory Management
Fixed Partition Storage Management
Segmented Paging Memory Management
B
null
1,823
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
For the relocated storage management method, one should ().
Set up a relocation register throughout the system.
Set a relocation register for each program.
Set two relocation registers for each program.
Set a relocation register for each program and data.
A
null
1,824
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Converting the logical addresses used in the working space to physical addresses in memory is called ().
Loading
Relocation
Physical Chemistry
Formalization
B
null
1,825
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
In segmented distribution, the CPU needs () memory accesses each time it fetches data from memory.
1
3
2
4
C
null
1,826
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The operating system adopts a paging storage management method, which requires ().
Each process has its own page table, and the page table of the process resides in memory.
Each process has a page table, but only the page table of the executing process resides in memory.
All processes share a single page table to conserve limited memory space, but the page table must reside in memory.
All processes share a single page table, and only the pages currently in use in the page table must reside in memory to maximize the conservation of limited memory space.
A
null
1,827
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Virtual storage technology is ().
Techniques for Supplementing Physical Memory Space
Techniques for Supplementing Logical Memory Space
Techniques for Supplementing External Storage Space
Techniques for Expanding Input/Output Buffers
B
null
1,828
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
To ensure that the virtual memory system functions effectively as intended, the characteristic that the running program should possess is ().
The program should not contain excessive I/O operations.
The size of the program should not exceed the actual memory capacity.
The program should have good locality.
The instruction relevance of the program should not be excessive.
C
null
1,829
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The main characteristic of demand paging storage management is ().
Eliminated the fractional part within the page.
Expanded the memory
Facilitates dynamic linking
Facilitates information sharing
B
null
1,830
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The storage management methods that provide virtual storage technology include ().
Dynamic Partition Storage Management
Paged Memory Management
Segmented Memory Management Request
Storage Overwriting Technology
C
null
1,831
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
When using swapping technology, if a process is in the middle of a critical section (), it cannot be swapped out of main memory.
Create
I/O operations
In the critical section
Deadlock
B
null
1,832
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
In storage management, the purpose of employing overlay and swapping techniques is ().
Save main memory space
Physically expanding the main memory capacity
Improve CPU Efficiency
Implementing main memory sharing
A
null
1,833
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Memory protection needs to be implemented by the () to ensure that the process space is not accessed illegally.
Operating System
Hardware Organization
The operating system collaborates with the hardware architecture.
The operating system or hardware architecture operates independently.
C
null
1,834
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
In variable partition management, the purpose of using compaction technology is ().
Merge free space
Merge Partition
Increase main memory capacity
Facilitate address translation
A
null
1,835
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
When using the best-fit allocation algorithm in partition management, the free areas are registered in the free area table in () order.
Increasing length
Decreasing length
Incremental Addressing
Address Decrement
A
null
1,836
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The pages in a paging system are for ().
user-perceived
The operating system perceives
perceived by the compilation system
The perceived connection assembly program
B
null
1,837
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
In page-based memory management, the starting address of the page table is stored in ().
memory
Page Table Storage
Translation Memory
Register
D
null
1,838
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
When using segmented storage management, how a program is divided into segments is determined at ().
Allocate Main Memory
User Programming
Assignment Submission
Program Execution
B
null
1,839
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The following () method is conducive to the dynamic linking of the program.
Segmented Storage Management
Paging storage management
Variable Formula Partition Management
Fixed Partition Management
A
null
1,840
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Reentrant programs improve system performance through the () method.
Change the length of the time slice
Change in the number of users
Increase the exchange rate
Reduce the number of permutations
D
null
1,841
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Dynamic partitioning, also known as variable partitioning, is established dynamically during the system's runtime ().
During job loading
At the time of assignment creation
Upon completion of the assignment
When the assignment is not loaded
A
null
1,842
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The purpose of storage management is ().
Convenient for users
Improve memory utilization
Facilitate users and enhance memory utilization.
Increase the actual capacity of memory
C
null
1,843
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Access to the main memory, ().
in blocks (i.e., pages) or segments
In bytes or words
Varies with different memory management schemes
Based on the unit of user's logical records
B
null
1,844
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
In paging storage management, the allocation of main memory ()
Perform operations in units of physical blocks.
Based on the size of the task
Addressing by physical segments
Based on the size of logical records
A
null
1,845
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Which of the following is not a characteristic of virtual memory? ().
Disposable
Multiple times
Commutativity
Discreteness
A
null
1,846
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The difference between demand paging and basic paging storage management is ()
Address Redirection
There is no need to load the entire assignment into memory.
Using fast table technology
There is no need to load the assignment into a contiguous area.
B
null
1,847
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
Maximum capacity of virtual memory ().
For the sum of internal and external memory capacity
Determined by the computer's addressing structure
is arbitrary
Determined by the address space of the task.
B
null
1,848
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The foundation of the virtual storage management system is the theory of ().
Dynamic nature
Virtuality
Locality
globality
C
null
1,849
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The () method can be used to implement virtual storage.
Partition Merge
Coverage, Exchange
Translation Memory
Segment Merging
B
null
1,850
Test
Operating System
Memory Management
Multiple-choice
Knowledge
English
The main characteristic of paged virtual memory management is ().
Do not require that the job be loaded into a contiguous area of main memory.
Do not require loading all tasks into a contiguous area of the main memory at the same time.
Do not require handling of page faults.
No page replacement is required.
B
null
1,851
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In segmented paging storage management, the address mapping table is ().
Each process has one segment table and two page tables.
Each process has a segment table for each of its segments, and a page table.
Each process has a segment table, and each segment has a page table.
Each process has one page table, and each segment has one segment table.
C
In a segmented paging system, a process is first divided into segments, and each segment is further divided into pages.
1,852
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In the variable partition allocation scheme, after a process is completed, the system reclaims its main memory space and merges it with adjacent free areas. This requires modifying the free area table, resulting in a decrease in the number of free areas by 1 when ().
No upper adjacent free space and no lower adjacent free space.
There is a free area above but no free area below.
There is a free block below but no free block above.
There is a free area above and a free area below.
D
Merge the upper adjacent free block, the lower adjacent free block, and the reclaimed block into one free block, thus reducing the number of free blocks by one. However, when there is only an upper adjacent free block or a lower adjacent free block, the number of free blocks does not decrease.
1,853
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
First Fit Algorithm's free partition ().
In descending order of size, connected together.
In increasing order of size, connected together.
Sorted in ascending order by address
Sort by address in descending order
C
The free partitions in the first-fit algorithm are arranged in ascending order of addresses.
1,854
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
The following statement about virtual memory is correct ().
Before execution, the job must be fully loaded into memory and must remain in memory throughout its execution.
Before execution, the job does not need to be fully loaded into memory, and it does not need to remain in memory throughout its execution.
Before execution, the job does not need to be fully loaded into memory, but it must remain in memory throughout the execution process.
Before execution, the job must be fully loaded into memory, but it does not need to remain in memory throughout the execution process.
B
In non-virtual memory systems, a job must be entirely loaded into memory and remain resident in memory during execution; in virtual memory systems, a job does not need to be entirely loaded into memory nor does it need to remain resident in memory throughout its execution. This is one of the main differences between vi...
1,855
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In page-based storage management, the selection of page size should consider the following () factors. Ⅰ. The advantage of larger pages is that there are fewer page tables. Ⅱ. The advantage of smaller pages is that they can reduce memory waste caused by internal fragmentation. Ⅲ. The main factor affecting disk access t...
Quadrants I and III
II and III
Type I and Type II
I, II, and III
C
Large pages result in fewer page tables for managing the pages, but lead to more internal fragmentation; small pages result in larger page tables, but less internal fragmentation. Appropriate calculations can yield an optimal page size and minimize system overhead.
1,856
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
An operating system manages memory using a paging storage management method, with a page size of ().
To determine based on the size of memory
Must be identical
To determine based on the CPU's address structure
Determine based on the size of external storage and internal memory.
B
An important issue in paging management is how to determine the page size. There are many factors to consider when determining page size, such as the average size of processes, the length occupied by the page table, etc. Once determined, all pages are of equal length (generally an integer power of 2) to facilitate syst...
1,857
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In segmented paging, the CPU needs () memory accesses to fetch data from memory each time.
1
3
2
4
B
In segmented paging, when fetching data, the segment table is first looked up in memory, then the corresponding page table is accessed in memory, and finally, after forming the physical address, memory is accessed, requiring a total of 3 memory accesses.
1,858
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
Among the following statements about paging storage, the correct one is (). Ⅰ. In paging storage management, if the TLB is turned off, the memory must be accessed twice whenever an instruction is accessed or an operand is fetched. Ⅱ. Paging storage management does not produce internal fragmentation. Ⅲ. Pages in paging ...
I, II, IV
I, IV
Only Ⅰ
All correct
C
Ⅰ Correct: After disabling the TLB, each time an instruction is accessed or an operand is fetched, the page table (in memory) must be accessed first to obtain the physical address, followed by another memory access to perform the corresponding operation. Ⅱ Incorrect: Remember, any fixed partitioning will result in int...
1,859
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In demand paging storage management, if the page size is doubled while the maximum number of pages that can be accommodated remains unchanged, the number of page faults during sequential program execution will ().
Increase
reduce
Invariant
May increase or decrease
B
In a demand paging system, as the page size increases, the number of page frames required to store a program decreases, thus reducing the frequency of page faults.
1,860
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
When a process encounters a page fault interrupt during execution, the operating system should handle it and then allow it to execute the () instruction.
The previous one that was interrupted
The interrupted one
The subsequent one that was interrupted
The first line upon startup
B
A page fault interrupt is caused by a memory access instruction, indicating that the page to be accessed is not in memory. After handling the page fault interrupt and loading the required page, the memory access instruction should clearly be re-executed.
1,861
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
The following statement about the page scheduling algorithm in demand paging systems is incorrect ().
A good page scheduling algorithm should reduce and avoid thrashing.
The FIFO algorithm is simple to implement; it selects the page that entered the main memory first for eviction.
The LRU algorithm is based on the principle of locality and first evicts the page that has not been accessed for the longest time in the recent period.
The CLOCK algorithm first evicts pages that have been frequently accessed over a period of time.
D
The CLOCK algorithm selects the least recently used page for replacement, hence it is also known as the NRU (Not Recently Used) algorithm.
1,862
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
Consider the page replacement algorithm, the system has m physical blocks available for scheduling, all initially empty, the length of the page reference string is p, containing n different page numbers, regardless of the algorithm used, the number of page faults will not be less than ().
m
p
n
min(m,n)
C
Regardless of the page replacement algorithm used, each page cannot be in memory upon its first access, inevitably resulting in a page fault. Therefore, the number of page faults is greater than or equal to n.
1,863
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
Assuming the main memory capacity is 1MB and the external memory capacity is 400MB, with the computer system's address register being 32 bits, then the maximum capacity of the virtual memory is ().
1MB
401MB
1MB + 2^32 MB
2^32B
D
The maximum capacity of virtual memory is determined by the computer's addressing structure and is not necessarily related to the capacity of the main memory or external storage. Its virtual address space is 2^32B.
1,864
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
The reason why the implementation of the LRU algorithm is costly is ().
Requires special support from hardware.
Requires a special interrupt handler.
Special page types need to be marked in the page table.
All pages need to be sorted.
D
The LRU algorithm requires recording the time since the last access for all pages and replaces the one that has not been accessed for the longest time, which involves sorting and is too costly for a replacement algorithm. Therefore, it is necessary to add LRU bits to the page table entries. Option A can be considered a...
1,865
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In the page table entries of a virtual memory system, what determines whether a page fault will occur is ().
Legal Position
Modify Bit
Page Type
Protection Code
A
The valid bit information in a page table entry indicates whether the page is in memory, thus determining whether a page fault will occur.
1,866
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In page replacement strategies, the () strategy may cause thrashing.
FIFO
LRU
There is no single
All
D
Thrashing is the behavior of frequent page scheduling (page faults) during the page replacement process of a program, and no page scheduling strategy can completely avoid thrashing.
1,867
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
The main cause of memory churn is ().
Insufficient memory space
The CPU is running too slowly.
The CPU scheduling algorithm is unreasonable.
The page replacement algorithm is unreasonable.
D
Memory thrashing refers to the phenomenon where pages in main memory are frequently evicted and then immediately loaded back in, only to be quickly evicted again. This is caused by an inefficient page replacement algorithm and is something that page replacement algorithms should strive to avoid.
1,868
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In page replacement algorithms, the algorithm that exhibits Belady's anomaly is ().
Optimal Page Replacement Algorithm (OPT)
First-In, First-Out replacement algorithm (FIFO)
Least Recently Used algorithm (LRU)
Recently Not Used algorithm (NRU)
B
FIFO is a queue-based algorithm that exhibits Belady's anomaly; options C and D are both stack-based algorithms, which can be theoretically proven not to exhibit Belady's anomaly.
1,869
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
In a virtual paging storage management system, if the page accessed by a process is not in the main memory and there are no free frames available in the main memory, the correct sequence of system handling is ().
Page Replacement → Page Eviction → Page Fault Interrupt → Page Fetch
Page Replacement → Page Fault → Page In → Page Out
Page Fault → Determine Page to Evict → Page Out → Page In
Page Fault → Page Replacement Decision → Page In → Page Out
C
According to the process of handling page faults, after a page fault occurs, the first step is to look for a free physical block in memory. If there are no free physical blocks available, a page replacement algorithm is used to determine which page to evict. Then, the evicted page is swapped out, followed by the swappi...
1,870
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
Given that the system uses a 32-bit physical address and a 48-bit virtual address, with a page size of 4KB and a page table entry size of 8B. Assuming the system employs pure paging, it will use a ()-level page table, and the page offset is () bits.
3, 12
3.14
4, 12
4, 14
C
The page size is 4KB, so the offset within a page is 12 bits. The system uses a 48-bit virtual address, so the virtual page number is 48-12=36 bits. When using a multi-level page table, the highest-level page table entries must not exceed one page size: the number of page table entries that can be accommodated per page...
1,871
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
Among the following statements, the correct one(s) is (are) (). Ⅰ. The First-In-First-Out (FIFO) page replacement algorithm can lead to Belady's anomaly. Ⅱ. The Least Recently Used (LRU) page replacement algorithm can lead to Belady's anomaly. Ⅲ. If all the pages of a process's working set are in virtual memory during ...
I, III
I, IV
II, III
II, IV
B
The FIFO algorithm may lead to Belady's anomaly. For example, with the page reference string 1,2,3,4,1,2,5,1,2,3,4,5, when 3 frames are allocated, there are 9 page faults, and when 4 frames are allocated, there are 10 page faults, so statement Ⅰ is correct. The Least Recently Used (LRU) algorithm does not produce Belad...
1,872
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
The measured partial state data of a computer system using a demand paging strategy are: CPU utilization is 20%, disk utilization for swap space is 97.7%, and the utilization of other devices is 5%. It is judged that the system is experiencing anomalies, and under these circumstances, () can improve system performance.
Install a faster hard drive
Increase swap space by expanding hard disk capacity.
Increase the number of running processes
Add RAM sticks to increase physical memory capacity.
D
The disk utilization rate for the swap space has reached 97.7%, while the utilization rate for other devices is at 5%, and the CPU utilization is at 20%. This indicates that, despite a low number of tasks, swapping operations are very frequent, leading to the conclusion that there is a severe shortage of physical memor...
1,873
Test
Operating System
Memory Management
Multiple-choice
Reasoning
English
Assuming a demand paging storage management system, the utilization rates of various related devices are measured as follows: CPU utilization is 10%, disk swap space utilization is 99.7%, and other I/O device utilization is 5%. The following measures () may improve CPU utilization: Ⅰ. Increase the capacity of memory Ⅱ....
I, II, III, IV
I, III
II, III, V
II, IV
B
I Correct: Increase the capacity of memory. Increasing memory allows each program to have more page frames, which can reduce the page fault rate, thereby reducing the swapping in/out process and improving CPU utilization. II Incorrect: Increase the capacity of the disk swap area. Since the system is already in a frequ...
1,874
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The information stored in the directory file is ().
The data information stored in a certain file
The file directory of a certain document
All data file directories in this catalog
The directory containing all subdirectory files and data files within this directory.
D
null
1,875
Test
Operating System
File Management
Multiple-choice
Knowledge
English
If multiple processes share the same file F, then among the following statements, the correct one is ().
Each process can only open file F in "read" mode.
There is only one entry in the system open file table that contains the attributes of F.
The entries for F in the user-level open file tables of each process are identical.
When a process closes file F, the system removes the entry for F from the system-wide open file table.
A
null
1,876
Test
Operating System
File Management
Multiple-choice
Knowledge
English
Access to a file is often restricted by ().
User access rights and file attributes
User access permissions and user priority
Priority and File Attributes
File Attributes and Password
A
null
1,877
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The logical structure of a file is designed for the convenience of ().
Storage Medium Characteristics
Operating System Management Methods
Main memory capacity
user
D
null
1,878
Test
Operating System
File Management
Multiple-choice
Knowledge
English
When a file exists on a tape, it is usually accessed using ().
Temporary storage method
Continuous and discrete storage methods
Discrete Storage Method
Sequential storage method
D
null
1,879
Test
Operating System
File Management
Multiple-choice
Knowledge
English
What is the function of a directory in achieving which of the following?
File's random access
Content-based file access
File's Named Access
Accessing files by size
C
null
1,880
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The file structure includes logical structure and physical structure. Logical structure refers to:
The structure in which users organize data is derived from requirements.
The organizational structure of physical data blocks in an operating system.
The organization of a file's name, extension, and path.
The organizational form of a file's physical location and storage method on the storage medium.
A
null
1,881
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The organization of physical files is determined by ().
Application Program
Main memory capacity
External storage capacity
Operating System
D
null
1,882
Test
Operating System
File Management
Multiple-choice
Knowledge
English
If there are two files with the same name in the file system, () should not be used.
Single-level directory structure
Two-level directory structure
Tree directory structure
Multi-level directory structure
A
null
1,883
Test
Operating System
File Management
Multiple-choice
Knowledge
English
In operating systems, input-output devices are commonly referred to as:
Peripheral Device
Special File
Virtual Device
Basic Components
A
null
1,884
Test
Operating System
File Management
Multiple-choice
Knowledge
English
From the user's perspective, the purpose of introducing a file system in an operating system is ().
Protecting User Data
Implement file access by name.
Implement virtual storage
Preserve user and system documents and data
B
null
1,885
Test
Operating System
File Management
Multiple-choice
Knowledge
English
In the UNIX operating system, input/output devices are treated as ().
regular file
Directory file
Index file
Special file
D
null
1,886
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The main task of opening a file operation is ().
Copy the directory of the specified file to the designated area in memory.
Copy the specified file to the designated area in memory.
Locate the directory of the specified file on the designated storage medium.
Search for the specified file in memory.
A
null
1,887
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The file directory entry of FAT32 does not include ().
File Name
File Access Permissions Description
Physical location of the File Control Block (FCB)
The physical location of the file
C
null
1,888
Test
Operating System
File Management
Multiple-choice
Knowledge
English
Some operating systems separate file descriptor information from directory entries, the benefit of doing this is ().
Reduce the amount of I/O when reading files
Reduce the amount of I/O when writing files.
Reduce the amount of I/O when searching for files
Reduce the amount of I/O data when copying files
C
null
1,889
Test
Operating System
File Management
Multiple-choice
Knowledge
English
Among the following statements, () falls within the category of a file's logical structure.
Continuous file
system file
Linked file
Streaming file
D
null
1,890
Test
Operating System
File Management
Multiple-choice
Knowledge
English
When using magnetic tape as a file storage medium, files can only be organized in ().
Sequential file
Linked file
Index file
Directory file
A
null
1,891
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The following is an inappropriate method for direct access allocation of external storage: ().
Continuous Distribution
Link Allocation
Index Allocation
All of the above answers are suitable.
B
null
1,892
Test
Operating System
File Management
Multiple-choice
Knowledge
English
If the physical structure of a file in the file system adopts a contiguous structure, the information about the physical location of the file in the FCB should include () Ⅰ. Starting block address Ⅱ. File length Ⅲ. Index table address
Only Ⅰ
I, II
II, III
I, III
B
null
1,893
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The file system creates an index table () for each file, which stores the disk locations of the file's data blocks.
Open the file table
Bitmap
Index Table
Free block linked list
C
null
1,894
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The relative path name of a file starts from (), and is a string composed of all the subdirectory names along the entire path, tracing step by step through each level of subdirectories, finally leading to the specified file.
Current directory
root directory
Multi-level Directory
Secondary Directory
A
null
1,895
Test
Operating System
File Management
Multiple-choice
Knowledge
English
The purpose of the file system adopting a multi-level directory structure is ().
Reduce system overhead
Save storage space
Resolve naming conflicts
Shorten the transmission time
C
null
1,896
Test
Operating System
File Management
Multiple-choice
Knowledge
English
Among the following options, () is not an object type defined by the Linux implementation of the Virtual File System (VFS).
Superblock object
inode object
File object
Data object
D
null
1,897
Test
Operating System
File Management
Multiple-choice
Reasoning
English
In the file system, the following is not a method of file protection ().
Password
Access Control
User Permissions Table
After reading and writing, use the close command.
D
In file systems, passwords, access control, and user permission tables are common methods of file protection.
1,898
Test
Operating System
File Management
Multiple-choice
Reasoning
English
The following statement about the index table is () correct.
Each record in the index table can have multiple index entries.
When accessing an indexed file, it is necessary to first search the index table.
The index table contains data of the index files and their physical addresses.
One of the purposes of creating an index is to reduce storage space.
B
An index file consists of a logical file and an index table. When accessing an index file, the index table must be searched first. Each index entry contains only the length of the record and its starting position in the logical file. Since each record must have an index entry, this increases the storage cost.
1,899
Test
Operating System
File Management
Multiple-choice
Reasoning
English
In the physical structure of the following document, what is not conducive to the dynamic growth of file length is ().
Continuous Structure
Linkage structure
Index structure
Hash structure
A
The requirement for continuous storage space means that the size of the file must be known in advance, so that a sufficiently large storage area can be found in the storage space based on its size. If the file grows dynamically, the space it occupies will become increasingly large. Even if the final size of the file is...
1,900
Test
Operating System
File Management
Multiple-choice
Reasoning
English
Assuming a log file that uses linked allocation, with a fixed logical record length of 100B, and employs record clustering technique for storage on disk. The disk block size is 512B. If the directory entry for the file has already been loaded into memory, then after modifying the 22nd logical record, the disk is access...
3
4
5
6
D
The 22nd logical record is stored in the 5th physical block (22x100/512=4, remainder 152). Since the file uses a linked file physical structure, it is necessary to start reading from the first physical block pointed to by the directory entry, which requires initiating the disk 5 times. After modification, a write-back ...
1,901
Test
Operating System
File Management
Multiple-choice
Reasoning
English
The correct statement about index files is ().
In the index file, each entry in the index table contains the key of the corresponding record and the physical address where the record is stored.
When retrieving a sequential file, the first step is to read the first block number of the file from the FCB; whereas, when retrieving an indexed file, one should first read the starting address of the file index block from the FCB.
For a file with a three-level index, accessing a record typically requires three disk accesses.
When dealing with large files, whether performing sequential access or random access, using an indexed file method is usually the fastest.
B
The entries in the index table contain the key of the corresponding record and the logical address where the record is stored; a three-level index requires four disk accesses; index files are fast for random access, while sequential files are fast for sequential access.
1,902
Test
Operating System
File Management
Multiple-choice
Reasoning
English
In a file system, where the FCB occupies 64B and the block size is 1KB, a single-level directory is used. Assuming there are 3200 directory entries in the file directory, the average number of disk accesses required to locate a file is ().
50
54
100
200
C
The number of disk blocks occupied by 3200 directory entries is 3200x64B/1KB=200 blocks. Since the average number of disk accesses for a single-level directory is 1/2 the number of blocks (sequentially searching through all the directory entries in the directory table, with each entry being an FCB), the average number ...
1,903
Test
Operating System
File Management
Multiple-choice
Reasoning
English
The correct statement about directory indexing is ().
Due to the faster retrieval speed of hashing, modern operating systems have replaced the traditional sequential search method with it.
When using the sequential search method, the file's pathname should be used for the tree directory, and the search should start from the root directory and proceed level by level.
When using the sequential search method, the search should be stopped as soon as one component of the pathname is not found.
After completing the search using the sequential search method, the physical address of the file can be obtained.
C
To implement user access to files by name, the system first uses the filename provided by the user to form a search path and searches the directory. In sequential search, if a component of the pathname is not found, it indicates that a certain directory or file in the pathname does not exist, and there is no need to co...
1,904
Test
Operating System
File Management
Multiple-choice
Reasoning
English
Among the following statements, the incorrect one is (). Ⅰ. A duplicate file of the same file on different storage media within the same system should use the same physical structure Ⅱ. Access to a file is often restricted by both user access permissions and user priority Ⅲ. After adopting a tree directory structure fo...
II
I, III
I, III, IV
Select All
D
Files on tape are usually stored sequentially, while this method is not commonly used on hard disks, and random access is used in memory, Statement I is incorrect. Access control to files is often restricted by both user access rights and file attributes, Statement II is incorrect. In a tree directory structure, files ...
1,905
Test
Operating System
File Management
Multiple-choice
Reasoning
English
If a bitmap composed of 8 words (word length of 32 bits) is used to manage memory, assuming that a user returns a memory block with a block number of 100, its corresponding position in the bitmap is ().
Font size is 3, bit position is 5.
Font size is 4, bit position is 4.
Font size is 3, bit position is 4.
Font size is 4, bit position is 5.
B
First, determine the row number where block number 100 is located. Blocks 1~32 are in row number 1, 33~64 in row number 2, 65~96 in row number 3, and 97~128 in row number 4. Therefore, block number 100 is in row number 4. Next, determine the column of block number 100 in row number 4. The first column in row number 4 i...
1,906
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
The buffer pool in buffering technology is in ().
Main Memory
external storage
Read-Only Memory
Register
A
null
1,907
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
In the SPOOLing system, the user process is actually allocated to the ().
The peripherals requested by the user
External storage area, i.e., virtual device.
A portion of the device's storage area
Part of the equipment's space
B
null
1,908
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
Virtual devices refer to ().
Allow users to use more devices than the physical devices present in the system.
Allow users to utilize physical devices in a standardized manner.
Transform a physical device into multiple corresponding logical devices.
Allow user programs to use devices in the system without having to load entirely into main memory.
C
null
1,909
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
To facilitate the development of higher-level software, device controllers usually need to provide ().
Control registers, status registers, and control commands.
I/O Address Register, Operating Mode Status Register, and Control Commands
Interrupt Register, Control Register, and Control Command
Control registers, programming space, and control logic registers.
A
null
1,910
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
In device management, the role of the Device Mapping Table (DMT) is ().
Manage physical devices
Manage Logical Devices
Implement input/output
Establish the correspondence between logical devices and physical devices.
D
null
1,911
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
DMA mode establishes a direct data path between ().
I/O devices and main memory
Two I/O devices
I/O devices and CPU
CPU and main memory
A
null
1,912
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
Channels, also known as I/O processors, are used to implement information transmission between ().
Memory and Peripherals
CPU and peripherals
Memory and External Storage
CPU and external storage
A
null
1,913
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
In operating systems, () refers to a type of hardware mechanism.
Channel Technology
Buffer Pool
SPOOLing technology
Memory Overwriting Technique
A
null
1,914
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
In computer systems, what does not belong to the DMA controller is ().
Command/Status Register
Memory Address Register (MAR)
Data Register
Stack Pointer Register
D
null
1,915
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
() is used to connect a large number of low-speed or medium-speed I/O devices.
Data Selection Channel
Byte Multiplexing Channel
Data Multiplexing Channel
I/O processor
B
null
1,916
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
In the following question, () is not an issue that should be considered in device allocation.
Timeliness
Inherent attributes of the equipment
Device Independence
Safety
A
null
1,917
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
The incorrect statement regarding device management is ().
Channels are software that handle input/output.
The startup operations for all devices are uniformly managed by the system.
The I/O interrupt events from the channel are handled by the device manager.
The well-prepared channel program is stored in the main memory.
A
null
1,918
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
A computer system is configured with 2 plotters and 3 printers; to properly drive these devices, the system should provide () device drivers.
5
3
2
1
C
null
1,919
Test
Operating System
Input/Output Management
Multiple-choice
Knowledge
English
The independence of the equipment refers to ().
The device is independent of the computer system.
The system's management of the device is independent.
The device used by the user during programming is independent of the actual device in use.
Each device has a unique identification number.
C
null