Fragmentation simply means wastage of memory now will it be internal or external that depends on your scheme.
Lets Break it Down Shall we...
Say i have a fixed memory allocation scheme and my partitions are of size 100 K,50K ,120 K.
Since we know that every partition can hold only one user program else there will be definite conflict in the address space which we cant allow. Now Suppose First fit policy is used and i wanna allocate a process of 50k. Can i do that of course i can. The algorithm will choose the First partition of size 100 k and allocate the 50k process to it now we have 50k size remaining inside that partiontion.Can we use it for another process. We cant because if we did then address conflict can be there inside a partition. When a fragmentation occurs within a partition that's what known as Internal Fragmentation.
Now Coming back to original Problem and Say i wanna allocate a new Process of Size 150 k Can i do that,No because there is no such partition in which i allocate the Process,All the partitions are empty but still we cant do it because of our poor scheming. Here this problem is known as External Fragmentation.(Compaction is not assumed for a while but still Compaction is Preferred in very low amount because in that time No useful work can be done)
Next Scheme is Variable length partition in which we have a big memory block of say 500 k,and when process start to arrive i will start giving them the Partition of the exact size they want. So no chance of Internal Fragmentation, Definitely external fragmentation can be there.
In question if it asks weather internal fragmentation is there ----------> Answer is NO.
But in practical situation we allow little bit internal fragmentation to occur.
We create a partition table where we store the information about every partition,there size,and are they free. If suppose after a very tremendous amount of allocations done there is a very small partition left of 10k. But we still have to write an entry for that, so what we do we simply merge it with an allocated partition to have a little bit of Internal Fragmentation. But that Rarely which we do.
So summary is :-
Fixed Allocation can suffer from both type of fragmentation but the Variable Length only with External Fragmentation.
