External and internal fragmentation

Question

Suppose that a total of 64MB RAM is available in a system. This memory space is partitioned into 8 fixed size slots of 8MB each. Assume 8 processes are currently requesting memory usage with sizes indicated as below: [2M, 4M, 3M, 7M, 9M, 6M, 1M, 8M] Calculate the size of memory wasted due to external and internal fragmentation. Assume more than one slot can be given to each process.

Comments

you missed the allocation 6.Last one i.e 8 will not get allocated

total = 6+4+5+1+7+2+7=32

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Oh so we have to follow a serial order while allocating? Can't we choose which one to not allocate so that internal fragmentation decreases?

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yep, they haven't mentioned which strategy to use. So go as per given order.

Answer 1

It is fixed partition scheme and slots are given which is fixed 8 mb each for process

1 process 1 came with 2 mb demand as per first fit scheme  we can place it in first block and 6 mb is wasted it is internal fragmentation

Then 2 to 8 process came accept 6 process each will get memory .. because 6 process is 9 mb is more than 8 mb as we know it is a fixed partition then the process will not get memory. Then external fragmentation occur which is 8 mb

And internal fragmentation is 25

Comments

I think from your logic internal fragmentation is 33 mb not 25