No /dev/sda created for USB Detachable Disk

[Peter Bonifacio]

Apologies if this information is easily available. I've searched the
archives and other sites but can't find the information I need.

I've just installed Feisty Fawn ( replacing a Debian install ). In the
process a removable usb hard disk /dev/sda does not seem to be
recognised. In fact there are no /dev/sd* devices at all. 
The disk seems to be seen by the kernel - but /dev/sda is not created. I
thought of using mknod to explicitly create the device but I'm not sure
of what the parameters should be. Can I derive this from the information
below?

Much appreciated.


Relevant section of lshw output is:

             *-usb:0
                   description: Mass storage device
                   product: Cypress AT2LP
                   physical id: 1
                   bus info: usb at 1:1
                   logical name: scsi2
                   version: 2.40
                   serial: DEF10B113EF4
                   capabilities: usb-2.00 scsi emulated scsi-host
                   configuration: driver=usb-storage maxpower=2mA
speed=12.0MB/s
                 *-disk UNCLAIMED
                      description: SCSI Disk
                      product: 6A
                      vendor: ST320082
                      physical id: 0.0.0
                      bus info: scsi at 2:0.0.0
                      version: 0000

Relevant section of dmesg is:

[91754.038923] usb-storage: device scan complete
[91754.042904] scsi 2:0:0:0: Direct-Access     ST320082 6A
0000 PQ: 0 ANSI: 0