Hi all,
I'm writing a script that uses rsync to sync 2 dirs on C7. I noticed a strange behaviour.
I have 2 dir: src and dest. In src dir I generate a testfile with "dd if=/dev/zero of=testfile bs=1M count=100" and when I run "du -h testfile" I get the correct result. Then I sync src/ to dest/ using "rsync -avS src/ dest/", all ok but when I run "du -h dest/testfile" I get 0 and if I run "du -b dest/testfile" I get the correct size in bytes.
I made several test to see what happens and noticed that removing -S (--sparse) from rsync command problem does not occour. In another test, thinking about a problem on 0ed file, I tried file generation using /dev/urandom then /dev/zero and running rsync -avS the problem is disappeared.
This not seems to be a CentOS 7 related problem. I tried also on Fedora 31 and get the same problem.
I wrote a simple bash script to replicate the problem:
#!/bin/bash mkdir src mkdir dest cd src #dd if=/dev/urandom of=testfile bs=1M count=100 dd if=/dev/zero of=testfile bs=1M count=100 echo "src/testfile size:" du -h testfile du -b testfile cd .. rsync -avS src/ dest/ > /dev/null echo "dest/testfile size after rsync --sparse:" du -h dest/testfile du -b dest/testfile rm -f dest/testfile echo "dest/testfile size after rsync:" rsync -av src/ dest/ > /dev/null du -h dest/testfile du -b dest/testfile
There is a bug in rsync or in du or something else?
Thanks in advance.