Re: question about Unmount/Eject on removable media menus

[David Zeuthen <david fubar dk>]

On Sun, 2009-05-10 at 06:36 -0400, Peter F. Patel-Schneider wrote:
> Hi:
> 
> I'm confused as to the actual difference between "Unmount Volume" and 
> "Eject Volume" for removable media.
> 
> I think I know how they might work:
> - Eject Volume would be for media in devices that have an actual eject 
> action (like CDs and floppies)
>      - it would first do an unmount and then perform the eject (if 
> possible - some media eject might not
>        be under software control)
> - Unmount Volume would be for other sorts of media
> 
> However this does not appear to be what is happening.
> 
> First, there is the warning in the Nautilus user documentation
> http://library.gnome.org/users/user-guide/stable/gosnautilus-464.html.en 
> in "To Eject Media" that says
> 
> You must unmount removable media before ejecting. Do not remove a USB 
> flash drive before you unmount the flash drive. If you do not unmount 
> the media first you might lose data.
> 
> Second, the "Eject Volume" entry seems to show up almost at random.  It 
> shows up for some of my USB keys, but not others; it shows up for a 
> PCMCIA to CF adapter.
> 
> Does anyone know what the situation is supposed to be?  Is it that 
> Nautilus just picks up on some property of the media provided by some 
> underlying layer?

Yes, it's all a bit confusing right now... There's some discussion here

 http://bugzilla.gnome.org/show_bug.cgi?id=576587

about what we want to do for GNOME 2.28.

It boils down to

 - If the device reports removable media, always show eject and make the
   default action for the Eject icon in the nautilus eject the media

 - Always show an Unmount item

Note that "eject" for devices that are not physically ejectable but
still reports that the media is removable, means that 

  - all volumes on the device will be unmounted; and

  - all volumes will disappear from the sidebar; and 

  - the device, if it has an user interface, will say "it is now safe
    to disconnect the device" or something to that effect.

Typical examples of devices that report removable media

  1. actual devices with removable media: optical drives, floppy drives,
     USB card readers, PCCard/Expresscard card readers, ZIP/Jaz drives

  2. virtually all USB sticks

  3. consumer electronics like iPod and Kindle and MP3 players

So for the devices in categories 1. through 3., the user experience is
that if you press the Eject icon in Nautilus, the volume will disappear
from the volume sidebar and the device will report "Safe to disconnect
to the device" or, if capable of physically ejecting the media (optical
drives and Zip drives only), eject the media. If you don't like this,
you can right click on the icon and select "Unmount" instead.

Typical examples of devices that report not having removable media

 4. USB and Firewire hard disk enclosures

 5. SATA and SCSI disks (typically the built-in disk)

 6. Built-in SD card readers (the card itself is the device, not the
    media)

and for these you will only get the "Unmount" option. Pressing the eject
icon in the Nautilus sidebar will not make the volume disappear (but the
eject icon will indeed disappear to signify the device is not mounted).

The above is pretty much the experience we want; in particular it means
that consumer electronics like Kindle- and iPod-ish devices will Just
Work(tm) without the need for any quirks/whitelists.

      David