Remove '.@__thumb' directories on QNAP

This could be useful if you don't plan to use any QNAP multimedia tools.

Disable Multimedia indexes generation

See QNAP documentation

If you can not delete some directories with SMB one reason could be some existing hidden index folder.

To delete the '.@__thumb' directories, connect using ssh:

# cd /share/CACHEDEV1_DATA/ or directory you want.

Then

find . -type d -name '.@__thumb' | while read ITEM; do rm -rfv "${ITEM}"; done