On Wed, Jan 15, 2020 at 11:38 AM Alessandro Baggi < alessandro.baggi at gmail.com> wrote: > Hi Jon, > I wrote in the first mail the script with the current order of command > that I used. Try to run in a bash script and you will see the result. > > If not my sequence is: > > dd if=/dev/zero of=src/testfile bs=1M count=100 > rsync -avS src/ dest/ > du -h dest/testfile > du -b dest/testfile > > for urandom: > > dd if=/dev/urandom of=src/testfile bs=1M count=100 > rsync -avS src/ dest/ > du -h dest/testfile > du -b dest/testfile > > without --sparse the same as first sequence without -S option. > > But why du reports 0M when with -b reports correct bytes and why this > happens only with zeroed file? > > Ah, I misunderstood what you meant. I had thought you might have created a file with urandom first and then overwrote it with zeros. This is behaving as expected with sparse files. You can create a sparse file with dd by using seek: https://www.thegeekdiary.com/how-to-create-sparse-files-in-linux-using-dd-command/