17.4.a Disk Geometry I - example syntax incorrect.
The lead-in to the example state the screenshot will show how we can view the geomtery with fdisk. This is then followed with a screenshot NOT showing the geometry using the the command "sudo fdisk -l /dev/sda".
I confirmed in 16.04 and 18.04 Ubuntu installs that this is not correct. Last this command worked were in 16.04 (I only work on LTS version so cannot comment on other versions.
The correct way to view this is with "sudo fdisk -l -u=cyliners /dev/sda"
as per man fdisk:
-u[=unit] When listing partition tables, show sizes in 'sectors' or in 'cylinders'. The default is to show sizes in sectors. For backward compatibility, it is possible to use the option without the <units> argument -- then the default is used. Note that the optional <unit> argument cannot be separated from the -u option by a space, the correct form is for example '-u=cylinders'.
sudo fdisk -l -u=cylinders /dev/sde
Disk /dev/sde: 55.9 GiB, 59961769984 bytes, 117112832 sectors
Geometry: 255 heads, 63 sectors/track, 7289 cylinders
Units: cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes