Du –exclude directories – is this possible

There are 2 parts to this question. First, why is there a difference between "Number of files" and "Number of files transferred". This is explained in the rsync manpage:

Number of files: is the count of all "files" (in the generic sense), which includes directories, symlinks, etc.

Number of files transferred: is the count of normal files that were updated via rsync’s delta-transfer algorithm, which does not include created dirs, symlinks, etc.

The difference here should be equal to the total amount of directories, symnlinks, other special files. Those were not "transferred" but just re-created.

Now for the second part, why is there a size difference with du. du shows the amount of disk space used by a file, not the size of the file. The same file can take up a different amount of disk space, if for example the filesystems blocksizes differ.

If you are still worried about data integrity, a easy way to be sure is to created hashes for all your files and compare:

( cd /home/hholtmann && find . -type f -exec md5sum {} \; ) > /tmp/hholtmann.md5sum
( cd /media/wd750/c51/home/ && md5sum -c /tmp/hholtmann.md5sum )

I came up with the following solution.

# exclude system created files like .DS_Store, desktop.ini...
arg="-C
"

# project each "$path" to "/$path/**" and concat 'em all
while read line || [[ -n $line ]]; do
    arg+="+ /$line/**
"
done < $subdirs

# */ - includes each folder so that rsync traverses the whole tree,
# *  - excludes everything else
arg+="+ */
- *"

# -m - excludes "empty" dirs that we used to traverse the tree
echo "$arg" | rsync -rmhvn -f ". -" --delete-excluded --info=PROGRESS2 --size-only $source/./ "$target"