usb printer connection problem

Discussion in 'Parallels Workstation for Windows and Linux' started by rsa4046, Mar 25, 2006.

  1. rsa4046

    rsa4046 Bit poster

    I'm running Parallels 2.1.1598, with windows XPsp2 as the guest, Gentoo Linux (2.6.15-gentoo-r7 kernel) as the host OS, and have an actual HP PSC 2410 serial printer/scanner connected to a real USB port. Parallels Tools is also installed within the XP guest. Printer works fine (hpiod driver, cups printing daemon) under Linux. When I reassert the USB device (plug/unplug the printer's usb cable) with the virtual XP machine running, a Parallels Workstation message box pops up, saying "Unable to connect USB device to virtual machine!". Is there a conflict with the host side? I've tried stopping the linux printer drivers (hpiod, cups, and samba) but this doesn't seem to help. Anyone have any ideas? The USB devices are present under the list of virtual devices. TIA!
  2. Nadine McSim

    Nadine McSim Junior Member

    First of all, please note Parallels Workstation 2.1 release ( is already available. I recommend to install it because it has some bugs fixed.
    If you receive the "Unable to connect USB device" message while trying to connect an USB device to your Virtual Machine on a computer running Linux primary OS, the most probable cause is that you do not have permissions to access USB devices. To fix the problem:
    1. Check if an usb-operating group exists in your Linux primary OS.
    2. If the group exists:
    * Include into this group users who have to have an access to USB devices.
    * Proceed to step 5.
    3. If the group does not exist:
    * Create a group and include into it users who have to have an access to USB devices.
    * In the /etc/fstab file edit the string that mounts the usbfs. Devgid parameter should contain the identifier of the group created in the previous step.

    usbfs /proc/bus/usb usbfs devgid=<USB gid>,devmode=0664 0 0

    This option will of course only work if you have the relevant support compiled into your kernel.
    4. Restart your Linux primary OS.
  3. rsa4046

    rsa4046 Bit poster

    Thanks, are you saying that Parallels-2.1.1598-lin.tgz is not 2.1?
    Thanks, I included myself in usb group, and no longer get the error message :), and XP now flashes a message that it has located a usb device. Under Device Manager, an Intel 82801Ba/BAM controller and USB Root Hub appear, but the printer itself appears as a USB composite device, and the driver fails to install from the CD (the printer does work under XP as the native OS). I'd appreciate any insight you have on this, or to learn if anyone else has gotten a USB printer to work under parallels. Also, the printer does work fine through Linux. Thanks again for your help! (Didn't see step 5, BTW)
  4. jensw

    jensw Member

    I think he meant 2.1.1658 is the current version (see download-page). It's just another build of 2.1 .

    Best regards,
    Jens Wannenmacher
  5. rsa4046

    rsa4046 Bit poster

    Thanks, I've gone ahead and installed the latest build (1658), and do see 2 usb devices listed under the Devices tab: "psc 2400 series", which is the same string reported by cups, and something called "USB printer:". Connecting to the former produces a "connection" chirp from XP, but it complains moments later that there is a problem with the device. Connecting to the latter effectively hangs linux, or at least the mouse and keyboard stop responding (although the XP guest appears to continue to function, icons at lower right screen border continue to flash, etc.).
  6. dglock2

    dglock2 Hunter


    The down load page has no build numbers, how are we supposed to know when a new build is available?

  7. anshar

    anshar Member

    Usually such news are sent by direct mails and posted as announces to forum. But I agree - better to have build number information directly on download page.
    Last edited: Apr 4, 2006
  8. jamesdodd

    jamesdodd Bit poster

    Can we FAQ?

    Can we make this sticky or add to FAQ etc

    didn't take long to find it, but in future it could do and its usefull
  9. anshar

    anshar Member

    I vote for FAQ!
  10. JochenH

    JochenH Bit poster

    My problem is, in Suse 10.0 there is no group "USB".

    Can you tell my what is the right group in Suse?
  11. constant

    constant Forum Maven


    The right group is "usb". If you don't have it, and we know you don't, then create a group called "usb" in Yast. Then make yourself, our the user who will need access to the usb device a member of that "usb" group.

    I made myself a member of the usb group and a deskjet printer that wouldn't be detected in XP all of a sudden was detected. I have a desktop shortcut in SuSE 10.0 KDE that starts Parallels with a preceding kdesu. That gets Parallels started as the root user, but only having my own user in the usb group did the trick for me. That and adding the line in fstab with devgid=1000, which is the gid that SuSE setup by default.

    Hope it makes sense now.
  12. JochenH

    JochenH Bit poster

    i maked a group "usb" and but the users in there.
    And i make the changes in the /etc/fstab with the devgid=34 <- this is the new group "usb".

    But all this changes have no effect:mad:

    When i start my vm (win2000) and i want connect the device in Parallesl over the Device Tab i get the message "Unable to connect ...."

    I have installed VMware and in the vm Windows 2000 too, on this vm there is no Problem with the USB.
  13. RickMaddy

    RickMaddy Member

    Won't work for me either

    I'm running PW 2.1 build 1670 under Linux SuSE 10.0 (kernel 2.6.13-15.8-default). I'm using Windows XP SP2 as the guest.

    My /etc/fstab has the line:

    usbfs /proc/bus/usb usbfs devgid=1000,busgid=1000,listgid=1000,devmode=0660,busmode=0770,listmode=0660,noauto 0 0

    Where 1000 is the gid of a group named usb of which I am a member.

    I've restarted Linux since making the fstab changes. PW still reports "Unable to connect USB device to virtual machine!" when I plug in the jump drive.

    I think this is a Linux issue because when I do an ls -l on /media the new directory for the usb device is owned by root:root and all the contents are too. What's even stranger is that if I keep doing an ls -l as I plug in the drive I see the initial creation of the directory as root with the correct permissions, then it changes to my user with the correct permissions then it changes back to root with 0777 permissions and then it stays there.

    Any ideas? Maybe something in KDE?


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