On Tue, Jan 7, 2025 at 10:07 AM Stefan Monnier <monn...@iro.umontreal.ca> wrote: > > > 8 TB is not that big. I have a external 18 TB drive. It is 18 TB in name > > only though! After fromating it with ext4 it only had 15TB of usuable > > space. > > 18TB "on paper" is usually 18 * 1000^4 bytes, so if you convert this > into "computer units" is ~16.37 * 1024^4 bytes. If you then make an > ext4 filesystem on it with the customary 5% reserved for root, that gets > you down to 15.5TB, to which you also have to remove the space used by > inodes, so yes, probably about 15TB and of course, once you start > putting actual files ion the drive, additional space will be used by > directories and metadata.
Also see "Gigabytes vs. gibibytes class action suit nears end", <https://www.cnet.com/culture/gigabytes-vs-gibibytes-class-action-suit-nears-end/>. The subtitle is, "Suit alleges companies misrepresent capacity of flash memory devices by using decimal definitions, thus overstating memory card sizes by 4 percent to 5 percent." The courts ruled a KB is 1000 bytes, not 1024 bytes, so the marketing departments won over the computer scientists. At least in California. Jeff
