Deck 14: File-System Implementation

Question 1

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.

Answer 1

C

Question 2

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

Answer 2

D

Question 3

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

A) 32
B) 64
C) 128
D) 256

Answer 3

A

Question 4

UNIX inode is an example of _______

A) a contiguous allocation.
B) a linked allocation
C) an indexed allocation
D) an index file

Question 5

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

Question 6

Indexed allocation

A) supports direct access
B) does not suffer from external fragmentation.
C) all of the above
D) none of the above

Question 7

Sequential access can be optimized by

A) free-behind technology
B) read-ahead technology
C) all of the above
D) none of the above

Question 8

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

Question 9

Describe the role of the logical file system module.

Question 10

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.

Question 11

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

Question 12

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

Question 13

Describe UNIX inode concept.

Question 14

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

Question 15

_______________ 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

Question 16

What happens when a process closes the file?

Question 17

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

Question 18

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

Question 19

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

Question 20

When a boot control block may be empty?

Question 21

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

Question 22

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

Question 23

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

Question 24

What method of free space management is used by Oracle's ZFS file system?

Question 25

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

Question 26

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

Question 27

What is a double caching?

Question 28

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

Question 29

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

Question 30

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

Question 31

Solaris ZFS file system never overwrites blocks with new data.

Question 32

What is a role of fsck in UNIX?

Question 33

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

Question 34

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

Question 35

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

Question 36

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.