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1. The beginning of a free space bitmap looks like this after the disk partition

ID: 3914606 • Letter: 1

Question

1. The beginning of a free space bitmap looks like this after the disk partition is first formatted: 1000 0000 0000 0000 0000 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 8 blocks, the bitmap looks like this 1111 1111 1000 0000 0000 0000 0000 0000. Show the bitmap after each of the following actions:

File B is written, using 10 blocks

File C is written, using 9 blocks

File B is deleted

File A is deleted

File D is written, using 14 blocks

File E is written, using 3 blocks.

Show all steps or explanations please.

Explanation / Answer

Free space bitmap looks like

1000 0000 0000 0000 0000 0000 0000 0000

While Writing File A which is 8 blocks:---

It is writing to free unassigned space of 0's which looks like

1111 1111 1000 0000 0000 0000 0000 0000

1) First we have to write blocks to free space blocks in bitmap

2) Writing files to bitmap turns to '1' and Unassigned remains '0' and while we delete '1' turns to '0'

3) While we are deleting we have to delete particular assigned block only

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File B is written, using 10 blocks:-

*We have to write 10 blocks to unassigned space of bitmap like

1111 1111 1111 1111 1110 0000 0000 0000

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File C is written, using 9 blocks

1111 1111 1111 1111 1111 1111 1111 0000

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File B is deleted which means we have to delete particular B assigned(written) spaces and turn them to 0

1111 1111 1000 0000 0001 1111 1111 0000

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File A is deleted

1000 0000 0000 0000 0001 1111 1111 0000

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File D is written using 14 blocks

which means we have to assign where 0's exist....

1111 1111 1111 1110 0001 1111 1111 0000

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File E is written, using 3 blocks

1111 1111 1111 1111 1101 1111 1111 0000

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Final bitmap after writing and deleting files..

(*)...... 1111 1111 1111 1111 1101 1111 1111 0000

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