Last time I backed up my data by copying and pasting my home directory into my external hard drive. Since then, I have added and deleted files from my home directory. I want to update that directory in my hard drive, so that I back up only newly added files, and I don't have to make a second copy of my home directory. This takes less space and time.
Now the difficulty seems to be that the directory structure in my laptop has changed. Some file locations might have changed. There are newly added and deleted files. So I want to use ideally the Ubunthu command line, maybe rsync, so that for each file in my laptop home, it searches all files on my home directory on the external drive, and if it's found somewhere there, don't copy, if it's not found, copy it. If a corresponding sub-directory exists, new files are added there. If not, create the corresponding sub-directory.
In general how do you go about updating your existing backup?