I'm using Lubuntu and have an external hard drive.
I would like to safely unmount the external hard drive.
Clicking the eject button in the file manager unmounts the drive, but does not power it down. (EDIT: Clicking on mount and then unplugging the drive means, at least on my machine, that the drive is still spinning when it's unplugged. This isn't good for the drive, so it's not good for my data!)
Naturally, 'umount' does not perform this function.
I can issue 'sudo hdparm -Y /dev/sdb', but this still leaves the drive's light on and I don't think it syncs the drive.
I seem to recall 'sudo sdparm --command=stop /dev/sdb' powering the drive down appropriately in the past, but this doesn't seem to be working now, and it's a mystery as to why the GUI doesn't have an option to do this.