I have a directory called
my_projects_linux inside the Ubuntu file system, which contains all my work from many years. The directory contains files, subdirectories and so on.
For backup purposes, I occasionally copy this directory and all its contents to external hard drive.
Hence, the contents of my external drive look like:
/mounted_drive/my_projects_linux /mounted_drive/my_projects_windows # the same idea to backup Windows work
Hence, what I am looking is a command which:
Would work as
cp /home/my_projects_linux /mounted_drive/my_projects_linux
It should replace old files, subdirectories, files inside subdirectories, etc. in the external disk by the new content from my PC.
Be fast. It should only copy modified files or those that have been newly created. Given that the size of
my_projects_linuxis >50 GB, copying everything takes more than an hour, which is too slow. In reality often only a few MB have changed since last backup, so theoretically a copy can be made much faster.
How to do that?
I googled that cp with the
-u flag could possibly match my needs. Would that work (e.g. would it correctly handle subdirectories of subdirectories)?
Also, is storing file system on an external disk an appropriate way of doing a backup, or is there a fancier way? For example, using a cloud? Note that the fancier way should be simple, as otherwise it will not outweigh the ease of executing one shell command.