User's Manual

Section E.1:Hard Disk Basic Concepts 103
Figure E–4 Disk Drive with Data Written to It
As Figure E–4, Disk Drive with Data Written to It shows, 14 of the previously-empty blocks are now
holding data. However, by simply looking at this picture, we cannot determine exactly how many files
reside on this drive. There may be as few as one or as many as 14 files, as all files use at least one
block and some files use multiple blocks. Another important point to note is that the used blocks do
not have to form a contiguous region; used and unused blocks may be interspersed. This is known as
fragmentation. Fragmentation can play a part when attempting to resize an existing partition.
As with most computer-related technologies, disk drives changed over time after their introduction. In
particular, they got bigger. Not larger in physical size, but bigger in their capacity to store information.
And, this additional capacity drove a fundamental change in the way disk drives were used.
E.1.2 Partitions: Turning One Drive Into Many
As disk drive capacities soared, some people began to wonder if having all of that formatted space in
one big chunk was such a great idea. This line of thinking was driven by several issues, some philo-
sophical, some technical. On the philosophical side, above a certain size, it seemed that the additional
space provided by a larger drive created more clutter. On the technical side, some filesystems were
never designed to support anything above a certain capacity. Or the filesystems could support larger