Contiguous allocation of files leads to disk fragmentation, as mentioned in the text, because some space in the last disk block will be wasted in files whose length is not an integral number of blocks. Is this internal fragmentation or external fragmentation

The answer is internal fragmentation.

Explanation:

Internal fragmentation occurs when a process needs more space than the size of allotted memory block because of the contiguous allocation of files.

On the other hand, external fragmentation occurs when a process is removed from the main memory. There are non-contiguous allocation of files that make memory blocks cannot be assigned to any process.

Disk Fragmentation

Disk fragmentation is one of the issues of the working framework. Disk fragmentation happens inside the record when the single document isn't situated in the equivalent physical memory area on the disk space and is spread around the disk. Disk fragmentation is fundamentally of two sort's to be specific outside fragmentation and the inward fragmentation. An outside fragmentation is one that alludes to the irregular access memory the executives with little and unused openings that are dissipated all through the plate. An inside fragmentation is one that incorporates a paging plan in the working framework.

Accordingly the capacity that is squandered, is available in the middle of the designation units of records, and is absent inside the documents therefore this is called as the outer fragmentation. As, the technique is decisively similar to fundamental memory outside fragmentation in this manner it happens with the framework swapping or utilizing the frameworks unadulterated division.