I have 3 USB sticks with 1 GB, 16 GB, 32 GB.
All are formatted with FAT 32 filesystem.
When I copy with cpa, then no error occurs.
When I use rsync -av, then next mount, dmesg gives the following error:
dirty bit, stick not properly unmounted. Run fsck.
The stick was correctly unmounted and the copy process did finish completly.
I have the following USB sticks:
1. Telekom: gratis 1 GB stick
2. Verbatim: 16 GB stick
3. Sony: 32 GB stick
With all have the same error does occur.
Can be the firmware of the sticks or something else.