Andrew S. Tanenbaum (OS) Edition 4 Exercise 4 Question 25 (Page No. 334)

Question

The beginning of a free-space bitmap looks like this after the disk partition is first formatted$:\: 1000\: 0000\: 0000\: 0000$ (the first block is used by the root directory). The system always searches for free blocks starting at the lowest-numbered block, so after writing file $A,$ which uses six blocks, the bitmap looks like this$:\: 1111\: 1110\: 0000\: 0000.$ Show the bitmap after each of the following additional actions:

1. File $B$ is written, using five blocks.
2. File $A$ is deleted.
3. File $C$ is written, using eight blocks.
4. File $B$ is deleted.

Answer 1

Action	Bitmap State
File B is written, using five blocks.	1111 1111 1111 0000
File A is deleted.	1000 0001 1111 0000
File C is written, using eight blocks.	1111 1111 1111 1100
File B is deleted.	1111 1110 0000 1100