Изящное выключение USB-накопителей перед отключением

Use udisksctlpara apagar la unidad:

   power-off
       Arranges for the drive to be safely removed and powered off. On the OS side this includes ensuring that
       no process is using the drive, then requesting that in-flight buffers and caches are committed to stable
       storage. The exact steps for powering off the drive depends on the drive itself and the interconnect
       used. For drives connected through USB, the effect is that the USB device will be deconfigured followed
       by disabling the upstream hub port it is connected to.

por ejemplo,.

udisksctl power-off --block-device /dev/sdb

Puede ejecutar el comando como un usuario normal, sin necesidad de acceso de root.
Si prefiere una interfaz gráfica de usuario, gnome diskstiene un botón para "apagar este disco" .