Data Movement in Linux – Often No More than Renaming
Strictly speaking the file still has not moved. The data bits are still on the same part of the disk where they were in the first place originally. The file specification ( the-directory-path plus the filename) that you use to talk about the file is different so that it appears to have moved , whereas it has not in actuality.
In early versions of Unix , the users were not allowed to use mv to move a file from one disk partition to another , you could only copy it ny using the cp(1) command. Linux allows you to use the mv command to move a file anyplace. Normally , mv leaves the data in place and just changes the file name or the directory where the name is placed. But when the file is moved across the disk partitions ( for example form /usr to /home in a lot of Linux systems) , the data is copied to the new disk partition, the new name is put in place. In that partition’s directory structure, and the name and file data are removed from the old disk partition.