From my reading of the gnome-vfs code and documentation, GnomeVFSDrives are
meant to represent physical drives on the system, and GnomeVFSVolumes represent
mounted partitions on those drives (in the case of a drive with no partitioning,
you'd get a single volume on the drive).

This problem exists with both the support existing in Gnome-VFS currently, and
with the following patch from David Zeuthen:
    http://lists.gnome.org/archives/gnome-vfs-list/2004-September/msg00066.html
(It appears that this patch was applied in the Fedora Core 3 packages, which is
why I tried it too).

Without the above patch, the output of test/test-volumes (modified to print HAL
UDI paths) on my system is:

Mounted volumes:
vol(0x53ccd0)[dev: /dev/sdb1, mount: file:///media/KINGSTON, device type: 3,
handles_trash: 1, icon: gnome-dev-harddisk-usb, name: KINGSTON, user_visible: 1,
drive: 0x53c6e0, udi: /org/freedesktop/Hal/devices/block_163B-01E6]
vol(0x53c060)[dev: /dev/sda1, mount: file:///boot, device type: 3,
handles_trash: 1, icon: gnome-dev-harddisk, name: Linux Disk, user_visible: 0,
drive: 0x53c5b0, udi: /org/freedesktop/Hal/devices/block_8_1]
vol(0x53bef0)[dev: /dev/sda5, mount: file:///, device type: 3, handles_trash: 1,
icon: gnome-dev-harddisk, name: Linux Disk (2), user_visible: 0, drive:
0x53c480, udi: /org/freedesktop/Hal/devices/block_8_5]
vol(0x53bda0)[dev: /dev/sda8, mount: file:///home, device type: 3,
handles_trash: 1, icon: gnome-dev-harddisk, name: Linux Disk (3), user_visible:
0, drive: 0x53c350, udi: /org/freedesktop/Hal/devices/block_8_8]
Connected drives:
drive(0x53c6e0)[dev: /dev/sdb1, mount: file:///media/KINGSTON, device type: 3,
icon: gnome-dev-removable-usb, name: DataTraveler2.0, user_visible: 1, volume:
0x53ccd0, udi: /org/freedesktop/Hal/devices/block_163B-01E6]
drive(0x53c5b0)[dev: /dev/sda1, mount: file:///boot, device type: 3, icon:
gnome-dev-removable, name: WDC WD740GD-00FL, user_visible: 0, volume: 0x53c060,
udi: /org/freedesktop/Hal/devices/block_8_1]
drive(0x53c480)[dev: /dev/sda5, mount: file:///, device type: 3, icon:
gnome-dev-removable, name: WDC WD740GD-00FL (2), user_visible: 0, volume:
0x53bef0, udi: /org/freedesktop/Hal/devices/block_8_5]
drive(0x53c350)[dev: /dev/sda8, mount: file:///home, device type: 3, icon:
gnome-dev-removable, name: WDC WD740GD-00FL (3), user_visible: 0, volume:
0x53bda0, udi: /org/freedesktop/Hal/devices/block_8_8]
drive(0x53bac0)[dev: /dev/hda, mount: file:///media/cdrom0, device type: 4,
icon: gnome-dev-removable, name: CD-RW/DVD?RW, user_visible: 1, volume: (nil),
udi: /org/freedesktop/Hal/devices/block_3_0]

With the patch applied I get the following:

Mounted volumes:
vol(0x53da80)[dev: sysfs, mount: file:///sys, device type: 3, handles_trash: 0,
icon: gnome-dev-harddisk, name: sys, user_visible: 0, drive: (nil), udi: (nil)]
vol(0x53d940)[dev: usbfs, mount: file:///proc/bus/usb, device type: 3,
handles_trash: 0, icon: gnome-dev-harddisk, name: usb, user_visible: 0, drive:
(nil), udi: (nil)]
vol(0x53d800)[dev: proc, mount: file:///proc, device type: 3, handles_trash: 0,
icon: gnome-dev-harddisk, name: proc, user_visible: 0, drive: (nil), udi:
(nil)]vol(0x53d680)[dev: /dev/sdb1, mount: file:///media/KINGSTON, device type:
3, handles_trash: 1, icon: gnome-dev-harddisk-usb, name: KINGSTON, user_visible:
1, drive: (nil), udi: /org/freedesktop/Hal/devices/block_163B-01E6]
vol(0x53d510)[dev: /dev/sda8, mount: file:///home, device type: 3,
handles_trash: 1, icon: gnome-dev-harddisk, name: 53G Media, user_visible: 0,
drive: (nil), udi: /org/freedesktop/Hal/devices/block_8_8]
vol(0x53d3d0)[dev: tmpfs, mount: file:///dev/shm, device type: 3, handles_trash:
0, icon: gnome-dev-harddisk, name: shm, user_visible: 0, drive: (nil), udi: (nil)]
vol(0x53c650)[dev: devpts, mount: file:///dev/pts, device type: 3,
handles_trash: 0, icon: gnome-dev-harddisk, name: pts, user_visible: 0, drive:
(nil), udi: (nil)]
vol(0x53c510)[dev: none, mount: file:///dev, device type: 3, handles_trash: 0,
icon: gnome-dev-harddisk, name: dev, user_visible: 0, drive: (nil), udi: (nil)]
vol(0x53c3a0)[dev: /dev/sda1, mount: file:///boot, device type: 3,
handles_trash: 1, icon: gnome-dev-harddisk, name: 254M Media, user_visible: 0,
drive: (nil), udi: /org/freedesktop/Hal/devices/block_8_1]
vol(0x53c260)[dev: rootfs, mount: file:///, device type: 3, handles_trash: 0,
icon: gnome-dev-harddisk, name: Root Volume, user_visible: 0, drive: (nil), udi:
(nil)]
vol(0x53c160)[dev: /dev2/root2, mount: file:///, device type: 3, handles_trash:
1, icon: gnome-dev-harddisk, name: Root Volume (2), user_visible: 0, drive:
(nil), udi: (nil)]
Connected drives:
drive(0x53c050)[dev: /dev/fd0, mount: file:///media/floppy0, device type: 5,
icon: gnome-dev-removable, name: Floppy 1, user_visible: 1, volume: (nil), udi:
(nil)]
drive(0x53bd30)[dev: /dev/hda, mount: file:///media/cdrom0, device type: 4,
icon: gnome-dev-removable, name: CD-RW/DVD?R Drive, user_visible: 1, volume:
(nil), udi: /org/freedesktop/Hal/devices/block_3_0]

Both behaviours seem wrong to me.  The current CVS behaviour creates multiple
GnomeVFSDrives for a single physical drive (one for each partition listed in
/etc/fstab).  With the patch applied, pretty much all the mounted volumes lacked
a corresponding GnomeVFSDrive.

Ideally, I'd expect GnomeVFSDrives for /dev/sda (the hard disk), /dev/sdb (the
USB stick), /dev/hda (the cdrom) and /dev/fd0 (the floppy), and then have
GnomeVFSVolumes for any mounted partitions on those devices.

This would improve the user experience with multi-partition removable drives, so
you can unmount all associated volumes before disconnecting it.