[Bug 58706] Re: LED indicator on USB flash disk is not switch off after disk eject

Marcin 'Qrczak' Kowalczyk qrczak at knm.org.pl
Sun Sep 14 16:02:46 UTC 2008


I have a phone which can serve as USB storage with two partitions. My
observations:

* Right click in Nautilus has Unmount, not Eject; each partition is
unmounted separately; the phone display does not change from the
connected state. I will call that operation "unmount".

* 'eject /dev/sdb1' or 'eject /dev/sdc1' do only the unmount, with a
message: eject: unable to open `/dev/sdb1'

* 'sudo eject /dev/sdb1' or 'sudo eject /dev/sdc1' unmounts both
partitions; the phone displays that it is now safe to unplug. I will
call that operation "eject".

* Adding myself to group disk makes the eject program really eject (but
is of course dangerous, as it gives the user write access to the HD).
Doing 'sudo chmod o+r /dev/sdb1' has the same effect on eject, but of
course does not persist plugging the phone again.

* After the unmount, the partitions can be mounted from the Computer
window. After the eject, the partitions still display in the Computer
window until I unplug the cable, but cannot be mounted again.

I guess the situation can be summarized as follows:

USB storage supports an operation, let's call it "eject", which implies
unmounting all its partitions but is more than that. The default Ubuntu
Hardy provides no GUI to ejection, and no CLI which does not involve
sudo. The 'eject' program is able to eject, as long as the calling user
has permissions to the corresponding /dev/sd* (read access is enough),
which he does not by default.

I think access to USB ejection is valuable: even if it does not increase
safety (I am not sure about this), it is convenient to unmount all
partitions of a given device at once. Perhaps the permissions or uid:gid
of /dev entries of removable media should be different?

-- 
LED indicator on USB flash disk is not switch off after disk eject
https://bugs.launchpad.net/bugs/58706
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