What I am doing: I created a directory in root md transfernotebook worked and shows in the directory. I mounted the device usb to the directory mount /dev/sdm1 /transfernotebook lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS sda 8:0 0 119.2G 0 disk └─md126 9:126 0 119.2G 0 raid1 └─md126p1 259:0 0 119G 0 part /boot/efi sdb 8:16 0 119.2G 0 disk └─md126 9:126 0 119.2G 0 raid1 └─md126p1 259:0 0 119G 0 part /boot/efi sdc 8:32 0 232.9G 0 disk └─sdc1 8:33 0 232.9G 0 part └─md127 9:127 0 232.9G 0 raid1 /var /usr/local /srv /root /opt /boot/grub2/x86_64-efi /boot/grub2/i386-pc / sdd 8:48 0 232.9G 0 disk └─sdd1 8:49 0 232.9G 0 part └─md127 9:127 0 232.9G 0 raid1 /var /usr/local /srv /root /opt /boot/grub2/x86_64-efi /boot/grub2/i386-pc / sde 8:64 0 3.6T 0 disk └─sde1 8:65 0 3.6T 0 part └─md0 9:0 0 3.6T 0 raid1 /var/lib/libvirt sdf 8:80 0 7.3T 0 disk └─sdf1 8:81 0 7.3T 0 part └─md1 9:1 0 7.3T 0 raid1 └─md1p1 259:1 0 7.3T 0 part /home sdg 8:96 0 7.3T 0 disk └─sdg1 8:97 0 7.3T 0 part └─md1 9:1 0 7.3T 0 raid1 └─md1p1 259:1 0 7.3T 0 part /home sdh 8:112 0 3.6T 0 disk └─sdh1 8:113 0 3.6T 0 part └─md0 9:0 0 3.6T 0 raid1 /var/lib/libvirt sdi 8:128 1 0B 0 disk sdj 8:144 1 0B 0 disk sdk 8:160 1 0B 0 disk sdl 8:176 1 0B 0 disk sdm 8:192 1 57.7G 0 disk └─sdm1 8:193 1 57.7G 0 part /transfernotebook sr0 11:0 1 1024M 0 rom So, it is there and it is mounted. I then did: rsync /home/mercurio -aAXHv /transfernotebook and here must be the error. Rsync does the whole transfer without error. I do unmount the device I put it into the notebook to do rsync but all I see is the mounted usb with "lost and found". I go back on the PC, before the directoy is empty, after mounting the device to the directory it is correctly populated. Hence I have the directory correctly on the usb device, it is not empty. Were is my pitfall? And if the files are not there, were are they? The USB drive has been mounted as ext4. Why do I see 0 byte and lost and found only. P.S. I attributed the whole usb disk to the partition (primary) ext4 Thank you.