Re: Does anyone successfully use USB drive in Windows7 guest?

["André Weidemann" <Andre.Weidemann@web.de>]

Hi,

On 25.06.2011 03:32, Flypen CloudMe wrote:
> Hi,
>
> Does anyone successfully use USB drive in Windows7 guest? If I pass a
> USB drive to Windows7 guest, Device Manager may find this device but
> the USB mass storage driver can't be installed successfully. I have
> tried many times. Is the emulated USB controller is so old and
> Windows7 doesn't support it? I can't use PCI passthrough feature to
> pass the whole USB controller to VM, because the hypervisor also needs
> to use some USB ports.
>
> If I use Windows XP or Linux, the USB drive can work well.
>

Try the following when starting qemu-kvm. Replace sdX with your USB device.

...
-device usb-ehci,id=ehci \
-drive if=none,id=usbstick,file=/dev/sdX \
-device usb-storage,bus=ehci.0,drive=usbstick \
...

If would like to add the device while your VM is running, you may omit 
the last two lines and add this one instead:
-monitor telnet:127.0.0.1:11111,server,nowait,nodelay

Add the device using the two commands below:
echo "drive_add 0 id=usbdrive,if=none,file=/dev/sdX"| /bin/nc -w1 
127.0.0.1 11111
echo "device_add usb-storage,id=usbdrive,bus=ehci.0,drive=usbdrive"| 
/bin/nc -w1 127.0.0.1 11111

Remove the device by first ejecting the USB drive under Win7. Then use 
this line to remove the drive from the VM:
echo "device_del usbdrive"| /bin/nc -w1 127.0.0.1 11111

Regards
  André