File-System Implementation Complete Test Bank Chapter 14

Chapter 14

Multiple Choice Questions

1. The following characteristics of disks make them convenient for being the secondary storage:

A. it is possible to read a block from the disk, modify the block, and write it back into the same place

B. a disk can access directly any block of information it contains

C. all of the above

D. none of the above

Feedback: 14.1

Difficulty: Easy

2. The basic file systems _______________

A. reads and writes physical blocks on the storage device.

B. tracks unallocated blocks and provides them the when it is required.

C. manages directory structure.

D. is responsible for protection.

Feedback: 14.1

Difficulty: Medium

2.  _______________ is used to implement a file system.

A. A boot control block

B. A volume control block

C. A directory structure.

D. all of the above

Feedback: 14.2

Difficulty: Easy

3. UNIX inode is an example of _______

A. a contiguous allocation.

B. a linked allocation

C. an indexed allocation

D. an index file

Feedback: 14.4.3

Difficulty: Easy

4. What is the size of the bit vector of a 1TB disk with 512-byte blocks?

A. 2 MB

B. 2⁸ MB

C. 28 MB

D. 8 MB

Feedback: 14.5.1

Difficulty: Easy

5. The FAT method ______________

A. keeps information about the block where bit vector is stored.

B. employs space maps to manage information about free blocks.

C. does not store information about free blocks.

D. incorporates free-block accounting into the allocation data structure.

Feedback: 14.4.3

Difficulty: Easy

6. Using ____-bit pointers limits the size of a file to 4 GB.

A. 32

B. 64

C. 128

D. 256

Feedback: 14.6.1

Difficulty: Easy

7. In __________ write, the data are stored in the cache, and control returns to the caller.

A. a non-buffered

B. a buffered

C. an asynchronous

D. a synchronous

Feedback: 14.6.2

Difficulty: Medium

8. Indexed allocation

A. supports direct access

B. does not suffer from external fragmentation.

C. all of the above

D. none of the above

Feedback: 14.4.3

Difficulty: Easy

9. Unified virtual memory uses _____________ to cache both process page and file data

A. disk block caching

B. double caching

C. buffer caching

D. page caching

Feedback: 14.6.2

Difficulty: Hard

10. Sequential access can be optimized by

A. free-behind technology

B. read-ahead technology

C. all of the above

D. none of the above

Feedback: 14.6.2

Difficulty: Medium

11. WAFL (write-anywhere file layout)

A. is a file system dedicated to single user operating systems

B. is a distributed file system

C.  cannot provide files via NFS

D. can provide files via NFS, but not via CIFS

Feedback: 14.8

Difficulty: Medium

Essay Questions

1. Describe the role of the logical file system module.

Feedback: 14.1

Difficulty: Medium

2. When a boot control block may be empty?

Feedback: 14.2

Difficulty: Easy

3. What kind of in-memory information are used for file-system management?

Feedback: 14.2.1

Difficulty: Easy

4. What happens when a process closes the file?

Feedback: 14.2.1

Difficulty: Easy

5. What are the main drawback of a linear list of directory entries?

Feedback: 14.3.1

Difficulty: Easy

6. How may we combat the main disadvantage of fixed size hash table?

Feedback: 14.3.2

Difficulty: Hard

7. Why is the whole block not available to a user when linked allocation is used?

Feedback: 14.4.2

Difficulty: Medium

8. Describe UNIX inode concept.

Feedback: 14.4.3

Difficulty: Medium

9. Why should new allocation algorithms be developed for NVM (nonvolatile memory) devices?

Feedback: 14.4.4

Difficulty: Medium

10. What method of free space management is used by Oracle’s ZFS file system?

Feedback: 14.5.5

Difficulty: Hard

11. What is a double caching?

Feedback: 14.6.2

Difficulty: Hard

12. What is a role of fsck in UNIX?

Feedback: 14.7.1

Difficulty: Medium

13. Why should the permanent backup be stored far away from the regular backup?

Feedback: 14.7.4

Difficulty: Easy

True/False Questions

1. The I/O control level consists of device drivers and interrupt handlers to transfer information between the main memory and the disk system

Feedback: 14.1

Difficulty: Easy

2. The logical file system module includes the free-space manager.

Feedback: 14.1

Difficulty: Medium

3. The open() call returns a pointer to the appropriate entry in the system wide-open-file table.

Feedback: 14.2.2

Difficulty: Medium

4. Contiguous allocation of a file is defined by the address of the first block and length (in block units) of the file.

Feedback: 14.4.1

Difficulty: Medium

5. The file allocation table (FAT) has one entry for each block and is indexed by block number.

Feedback: 14.4.2

Difficulty: Easy

6. The FAT method incorporates free-block accounting into the allocation data structure.

Feedback: 14.5.2

Difficulty: Easy

7. The addresses of a given number of free blocks can be found faster using linked list rather than using grouping.

Feedback: 14.5.3

Difficulty: Medium

8. For counting method (used by free space management), the entries in the free-space list can be stored in a linked list, rather than a balanced tree, for efficient lookup, insertion, and deletion.

Feedback: 14.5.4

Difficulty: Medium

9. Storage devices that do not allow overwrite (such as NVM devices) need only the free list for managing free space.

Feedback: 14.5.6

Difficulty: Hard

10. The consistency check is always able to recover the structures, e.g., resulting in loss of files and entire directories.

Feedback: 14.7.2

Difficulty: Medium

11. Solaris ZFS file system never overwrites blocks with new data.

Feedback: 14.7.3

Difficulty: Medium