File Systems

Question 1

Information stored in files must be [p] and not affected by [p] [c] and [t]. A file should only [d] when its owner explicitly [r] it.

Answer 1

persistent
process
creation
termination
disappear
requests

Question 2

There are three essential requirements for files.

Answer 2

Store a large amount of information

Information should survive process termination

Multiple processes must be able to access information concurrently.

Question 3

A file is a type of [u]

Answer 3

unit

Question 4

A regular file…

Answer 4

contains user information

Question 5

Directories are…

Answer 5

special files for maintaining the file system

Question 6

Character special files

Answer 6

are related to input output and used to model I/O

Question 7

Block special files…

Answer 7

are used to model disks

Question 8

Sequential allocation allows a process…

Answer 8

to read bytes from a start to an end point. Not good at jumping around.

Question 9

Define random access files

Answer 9

files whose bytes and records can be read in any order

Question 10

Every file has [n] and [d]

Answer 10

name and data

Question 11

The extra information associated with a file are called its

Answer 11

attributes

Question 12

Record length, ley position and key length are only present in files…

Answer 12

…that are looked up using a key.

Question 13

Create() does what?

Answer 13

creates a file with no data.

Question 14

Delete() does what?

Answer 14

deletes a file

Question 15

Open() does what?

Answer 15

Allows system to fetch attributes and list of disk addresses into main memory.

Question 16

Write() does what?

Answer 16

data is written to a file, usually at the current position.

Question 17

Read() does what?

Answer 17

Data are read from file. Caller must specify how much.

Question 18

Append() does what?

Answer 18

A restricted form of write. Adds to end of file.

Question 19

File organisation needs to allow for [qa], [eu], [es], [sm] and [r]

Answer 19

quick access
easy update
economy of storage
simple maintenence
reliability

Question 20

An absolute path name

Answer 20

is the path to the requested file from the route

Question 21

A relative path name…

Answer 21

is used in conjunction with the working directory. path names are defined in relation to the working directory.

Question 22

tree structures allow…

Answer 22

several file names, provided the paths are different