[Discuss-gnuradio] GNURadio fresh Linux installation and usrp_benchmark_usb.py error

[Fabrizio Tappero]

Hello,
I am new in the GNU Radio community and I am looking for  some help to
get started.

I have installed Linux Ubuntu 9.10 (Karmic Koala) as Virtual Box host
in OS X 10.5.8.
following the "Getting Started" indications from:
http://gnuradio.org/redmine/wiki/gnuradio/UbuntuInstall

I successfully installed GNURadio 3.2.2 from the binary of
deb http://gnuradio.org/ubuntu stable main

by issuing ls -lR /dev/bus/usb | grep usrp I get:
crw-rw---- 1 root usrp 189, 2 2010-02-17 09:40 003

Which might mean that all went well. However following up the Ubuntu
Install indications in
http://gnuradio.org/redmine/wiki/gnuradio/UbuntuInstall

if I do:

cd /usr/share/gnuradio/examples/python/usrp
./usrp_benchmark_usb.py

I unfortunately get this:
Testing 2MB/sec... usrp: failed to find usrp[0]
Traceback (most recent call last):
  File "./usrp_benchmark_usb.py", line 106, in <module>
    main ()
  File "./usrp_benchmark_usb.py", line 96, in main
    ok = run_test (rate, verbose)
  File "./usrp_benchmark_usb.py", line 63, in run_test
    usrp_tx = usrp.sink_s (0, tx_interp)
  File "/usr/lib/python2.6/dist-packages/gnuradio/usrp/usrp_swig.py",
line 2736, in sink_s
    return _usrp_swig.sink_s(*args, **kwargs)
RuntimeError: can't open usrp

Can somebody please help me understand what I did wrong.
Thank you in advance for your help.

Vincent