qcow2 actual size

I am little bit confused with the real size of qcow2 files. ls -alh VMs/ubuntu-mini.qcow2 -rw------- 1 root root 21G mar 31 23:15 VMs/ubuntu-mini.qcow2 du -h VMs/ubuntu-mini.qcow2 2,7G VMs/ubuntu-mini.qcow2 I wanted to copy that file to different partition (ext4). It looks this command copied actually **21G** not only **2,7G** I expected. And now in new location these both commands (du and ls) shows me the same size - 21G. du -h /media/HDD0/VMs/ubuntu-mini.qcow2 21G /media/HDD0/VMs/ubuntu-mini.qcow2 ls -alh /media/HDD0/VMs/ubuntu-mini.qcow2 -rw------- 1 root root 21G mar 31 23:15 /media/HDD0/VMs/ubuntu-mini.qcow2 What's the proper way of copying qcow2 files? Is there are switch in "cp" command which makes it to copy only 2,7G?