Safely remove option shows with Micro SD Card connected to Linux through an Android phone

[prasannatsmkumar <prasannatsmkumar gmail com>]

Hi All,

I connected an Android phone using USB cable to my machine running Linux (Linux 3.0, 3.2, 3.5). Mounted the SD card in phone in system (phone is just a pass through I guess). When I choose "Safely Remove" option in nautilus file manager (gnome's default file manager) I got an error saying

"Error detaching: helper exited with exit code 1: Detaching device /dev/sdb
USB device: /sys/devices/pci0000:00/0000:00:1d.7/usb1/1-5)
SYNCHRONIZE CACHE: OK
STOP UNIT: FAILED: No such file or directory"

and it goes to unmounted state (yes it should go to and this is not a problem). But I am not able to find the reason for the above error message pop-up. If I choose "Eject" option then things are fine (I think Eject does more than un-mounting the file system).

I think "safely remove" tries to cut the power supply to the device but eject does not do that. Is that correct? If the device cannot be powered down (due to battery charging) why this option is shown? Is kernel exposing such capability to the user space?

I am not sure whether this is the correct place to ask this question. If this is not the correct place please direct me to correct place.

Thanks and Regards,
PrasannaKumar