This is probably one of the biggest mistakes I’ve dragged for more time as Linux user, in part for not reading the man pages and in part by assuming too much from the name of an executable.
When working with USB storage I was used to plug it, mount it, do some stuff with it, sync, unmount, eject and unplug it. And seems that eject does not apply to USB storage, only to “ejectable” media: CD/DVD/Floppies…
So, the right way to stop an USB storage device is to use:
sdparm --command=stop /dev/device
PS: I’m afraid that I was not the only unwary out there that was “ejecting” the USB storage before unplugging it, so I hope you can find this tip useful hehe 😀