I close SimpleScan, disconnect the scanner, then launch "udevadm monitor" : $ udevadm monitor monitor will print the received events for: UDEV - the event which udev sends out after rule processing KERNEL - the kernel uevent Then I connect my scanner : KERNEL[1288241931.390942] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/usb/hiddev0 (usb) KERNEL[1288241931.391017] remove /class/usb (class) KERNEL[1288241931.391065] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000E/hidraw/hidraw0 (hidraw) KERNEL[1288241931.391194] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000E (hid) KERNEL[1288241931.391250] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0 (usb) KERNEL[1288241931.391308] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2 (usb) UDEV [1288241931.397824] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/usb/hiddev0 (usb) UDEV [1288241931.397886] remove /class/usb (class) UDEV [1288241931.401398] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000E/hidraw/hidraw0 (hidraw) UDEV [1288241931.406700] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000E (hid) UDEV [1288241931.408624] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0 (usb) UDEV [1288241931.414562] remove /devices/pci0000:00/0000:00:13.0/usb2/2-2 (usb) KERNEL[1288241932.040298] add /devices/pci0000:00/0000:00:13.2/usb1/1-3 (usb) KERNEL[1288241932.048414] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.0 (usb) KERNEL[1288241932.049055] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1 (usb) KERNEL[1288241932.057449] add /class/usb (class) UDEV [1288241932.057511] add /class/usb (class) KERNEL[1288241932.057562] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1/usb/lp0 (usb) KERNEL[1288241932.061697] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2 (usb) KERNEL[1288241932.078207] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16 (scsi) KERNEL[1288241932.078284] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/scsi_host/host16 (scsi_host) UDEV [1288241932.095639] add /devices/pci0000:00/0000:00:13.2/usb1/1-3 (usb) UDEV [1288241932.103123] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2 (usb) UDEV [1288241932.105058] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16 (scsi) UDEV [1288241932.108403] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/scsi_host/host16 (scsi_host) UDEV [1288241932.128137] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.0 (usb) UDEV [1288241932.149813] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1 (usb) UDEV [1288241932.191906] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1/usb/lp0 (usb) KERNEL[1288241937.084169] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0 (scsi) UDEV [1288241937.085726] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0 (scsi) KERNEL[1288241937.086324] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0 (scsi) KERNEL[1288241937.089166] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_disk/16:0:0:0 (scsi_disk) KERNEL[1288241937.093121] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_device/16:0:0:0 (scsi_device) KERNEL[1288241937.093357] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_generic/sg2 (scsi_generic) KERNEL[1288241937.093505] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/bsg/16:0:0:0 (bsg) UDEV [1288241937.096645] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0 (scsi) UDEV [1288241937.098894] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_device/16:0:0:0 (scsi_device) UDEV [1288241937.100317] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_disk/16:0:0:0 (scsi_disk) UDEV [1288241937.107049] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_generic/sg2 (scsi_generic) UDEV [1288241937.107786] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/bsg/16:0:0:0 (bsg) KERNEL[1288241937.114859] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/block/sdb (block) KERNEL[1288241937.114897] add /devices/virtual/bdi/8:16 (bdi) UDEV [1288241937.117009] add /devices/virtual/bdi/8:16 (bdi) UDEV [1288241937.191678] add /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/block/sdb (block) Then disconnect my scanner: KERNEL[1288242038.600709] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.0 (usb) KERNEL[1288242038.600792] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1/usb/lp0 (usb) KERNEL[1288242038.600833] remove /class/usb (class) KERNEL[1288242038.600880] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1 (usb) KERNEL[1288242038.600930] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/bsg/16:0:0:0 (bsg) KERNEL[1288242038.600979] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_generic/sg2 (scsi_generic) KERNEL[1288242038.601031] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_device/16:0:0:0 (scsi_device) KERNEL[1288242038.601074] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_disk/16:0:0:0 (scsi_disk) KERNEL[1288242038.601115] remove /devices/virtual/bdi/8:16 (bdi) KERNEL[1288242038.601164] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/block/sdb (block) UDEV [1288242038.610890] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.0 (usb) UDEV [1288242038.610972] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1/usb/lp0 (usb) UDEV [1288242038.616071] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.1 (usb) UDEV [1288242038.616144] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_disk/16:0:0:0 (scsi_disk) KERNEL[1288242038.626439] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0 (scsi) KERNEL[1288242038.626515] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0 (scsi) KERNEL[1288242038.626556] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/scsi_host/host16 (scsi_host) KERNEL[1288242038.626598] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16 (scsi) KERNEL[1288242038.626646] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2 (usb) UDEV [1288242038.628302] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/scsi_host/host16 (scsi_host) KERNEL[1288242038.630465] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3 (usb) UDEV [1288242038.638382] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/block/sdb (block) UDEV [1288242038.645021] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_generic/sg2 (scsi_generic) UDEV [1288242038.647062] remove /devices/virtual/bdi/8:16 (bdi) UDEV [1288242038.648294] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/bsg/16:0:0:0 (bsg) UDEV [1288242038.649490] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0/scsi_device/16:0:0:0 (scsi_device) UDEV [1288242038.651165] remove /class/usb (class) UDEV [1288242038.660996] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0/16:0:0:0 (scsi) UDEV [1288242038.661075] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16/target16:0:0 (scsi) UDEV [1288242038.661120] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2/host16 (scsi) UDEV [1288242038.661170] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3/1-3:1.2 (usb) UDEV [1288242038.755408] remove /devices/pci0000:00/0000:00:13.2/usb1/1-3 (usb) KERNEL[1288242039.559085] add /devices/pci0000:00/0000:00:13.0/usb2/2-2 (usb) KERNEL[1288242039.562478] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0 (usb) KERNEL[1288242039.562708] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000F (hid) KERNEL[1288242039.574918] add /class/usb (class) KERNEL[1288242039.574996] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/usb/hiddev0 (usb) KERNEL[1288242039.575045] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000F/hidraw/hidraw0 (hidraw) UDEV [1288242039.579186] add /class/usb (class) UDEV [1288242039.587766] add /devices/pci0000:00/0000:00:13.0/usb2/2-2 (usb) UDEV [1288242039.592664] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0 (usb) UDEV [1288242039.601370] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/usb/hiddev0 (usb) UDEV [1288242039.604533] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000F (hid) UDEV [1288242039.610027] add /devices/pci0000:00/0000:00:13.0/usb2/2-2/2-2:1.0/0003:2101:0201.000F/hidraw/hidraw0 (hidraw)