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(a)Define the terms compaction
and coalescing [2marks ]
Compaction involves moving all occupied memory to one end and leaving
all unused contiguous storage space at the other end (1 mark), while
coalescing involves merging the adjacent free partitions into a single
partition (1 mark). Other valid answers should also receive credit.
[2 marks ]
(b)Show, using an example,how
compaction and coalescing work.[6 marks ]
Marks should be awarded as follows:
•Three marks should be awarded fo an example which demonstrates
excellent understanding of compaction;two marks should be awarded
fo an example which demonstrates adequate understanding of compaction;
one mark should be awarded for an example which demonstrates some
understanding of compaction;vno marks should be awarded otherwise.
•Three marks should be awarded fo an example which demonstrates
excellent understanding of coalescing; two marks should be awarded
fo an example which demonstrates adequate understanding of coalescing;
one mark should be awarded fo an example which demonstrates some understanding
of coalescing; no marks should be awarded otherwise.
[6 marks ]
(c)List three weaknesses
of compaction.[3 marks ]
One mark should be awarded for each weakness named (up to a maximum
of three marks). Examples include the following:
•It consumes system resources.
•It has an erratic response time.
•It involves the relocation of jobs. Other valid answers should
also receive credit. [3 marks ]
(d)Give one weakness of coalescing.[1 mark ]
The summation of the freed adjacent partition might not be enough
to un a process. Other valid answers should also receive credit. [1
mark ]
(e)Explain how spooling facilitates printing.[3 marks ]
To use a printer, the process needs to open the special character
file; if the file is open, no other processes can use it until it
is closed (1 mark).To prevent delays, a daemon process and a spooling
directory are created (1 mark).To print a file, the entire print file
is generated and kept in the spooling directory (1 mark). Other valid
answers should also receive credit.
[3 marks ]
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