I was making a backup today and this message appeared, after .tar.gz the directory

File shrank by 2014298112 bytes; padding with zeros

After googling a little, I found that the problem is not actually a problem it is just a file that has more space that it is really using, so it is reserving space for future use, and this makes sense because I was backing up a VMware virtual machine, and the file that gave me this error, was the virtual disk of that VM.