Powered USB Support

Discussion in 'Parallels Desktop for Mac' started by kenman, Jan 23, 2007.

  1. kenman

    kenman Bit poster

    Messages:
    3
    I have an IMAC (20").

    I am trying to get Windows (running in Parallels - 3120 R1) to recognize an external USB powered hard drive (Lacie 40 gig), but every time I connect the Lacie, Parallels freezes and I have to reset the VM.

    I called Lacie - and they sent me an additional USB cable because they said the single USB does not provide enough power to run the Lacie drive.

    I connected both USB cables to the IMAC and Windows still does not recognize the drive.

    Any ideas?
     
  2. nycruza

    nycruza Hunter

    Messages:
    224
    Go to Parallels Configuration Menu.
    Under shared folders add the external drive

    ajm
     
  3. dkp

    dkp Forum Maven

    Messages:
    1,367
    Does OS X recognize it? I think any drive that pulls that much power from the USB is not likely safe. I have a PPC laptop that is junk now because an external terrabyte HD smoked the MB when the power cord on the drive got disconnected. The USB standards are pretty clear about what loads can be imposed and it is expensive when a vendor breaks the rules.
     
  4. kenman

    kenman Bit poster

    Messages:
    3
    Yes, OSX recognizes it
     
  5. joem

    joem Forum Maven

    Messages:
    1,247
    There are lots of bus powered USB drives that draw more than the 500 ma at 5V that USB is rated to provide, and many of them come with cables to connect to two USB ports do double the power available (from 2.5 watts to 5 watts). If those drives are connected to two powered ports, they work fine. Part of the USB spec calls for current limiting so that an overload just shuts down the power without harming anything. If overloading a USB port causes damage to the port hardware, the hardware doesn't meet spec and is at fault.

    For the curious, the Firewire bus power spec is seven watts, but the voltage can vary over a very wide range and some ports will supply much more.
     
    Last edited: Jan 23, 2007
  6. mcqueary

    mcqueary Member

    Messages:
    20
    I have exactly the same problem as the original poster, only in a RedHat AS3 VM running in Parallels 3120RC1 on my Mac Pro. Both USB connectors are plugged into the front of my Mac Pro. OSX recognizes the drive, but the RH VM does not. I attach the USB device to the VM via the Devices menu, reset the VM, but when I log back in, "fdisk -l" shows only the VM's hdd, not the external ext2 USB drive.

    Any hints appreciated.
     
  7. mcqueary

    mcqueary Member

    Messages:
    20
    I have used this solution with (for instance) a thumb drive formatted with a FAT32 filesystem.

    The problem with this as a general solution is that it requires the external disk to be formatted with a filesystem that MacOS recognizes and can therefore mount. In my case, I am trying to use an EXT2 filesystem, which MacOS X does not natively recognize (without Brian Bergstrand's ext2fsx package, which is fragile/unreliable in my experience).

    Anyway, I want the VM to have direct access to the raw device so that I can e.g. format the external drive from my Linux VM, just as I would if I were running a physical box.

    Any other suggestions appreciated.

    Larry M.
     
  8. manack

    manack Bit poster

    Messages:
    5
    Additionally, does anyone else find that using shared folders to access /Volumes, such as an external USB2 drive, results in much slower read/write capabilities to that Volume than just native mounting of that device in the VM OS ?
     
  9. kenduit

    kenduit Member

    Messages:
    31
    Maxtor one touch 3 not working

    Hi
    Maxtor one touch 3 works ok on macbook pro useing usb2 but does not work in winxp2 vm.

    Does it work in the latest up date of paralles??? Thanks Ken
     
  10. mcqueary

    mcqueary Member

    Messages:
    20
    I haven't seen any evidence that suggests that any external USB drive (other than flash drives) work with the latest build (3120 RC1). None I have tried seem to work.
     
  11. str2000

    str2000 Bit poster

    Messages:
    2
    Same problem for me. I tried 2 USB Disks (FAT32 und NTFS) both are recognized in MacOS but not in XP running in the virtual machine. In the device manager a USB drive is shown, but it reports the drive as unreadable (properties/partitons) and so no drive letter is assigned.

    I hope they will fix it, because i'm very happy with parallels.
     
  12. str2000

    str2000 Bit poster

    Messages:
    2
    Seems to work with 3150 RC2 !!!!
     
  13. manack

    manack Bit poster

    Messages:
    5
    Under 3150 RC2, my USB2 external hard drive (2 FAT32 partitions) can mount finally. However it's definitely buggy at this stage, with it taking several minutes to mount (first makes desktop and taskbar unresponsive for a couple minutes and then an 'Autorun' program starts up and searches for a few minutes).

    Also it's unclear to me what the best sequence is for getting the USB2 ext HD connected, is it best to:

    1. Connect device, mount in OSX first, then start Parallels and VM? (doing this way seems to not unmount the drive from OS X cleanly with the 'this device not properly unmounted message' popping up in OS X)

    2. Start Parallels and VM, then connect device and mount?

    3. Start Parallels, connect device, start VM, then mount?

    Also I don't understand the autoconnect device feature, for me it does not autoconnect-- I still have to select 'USB to ATA/ATAPI bridge' to get WinXP to recognize.
     
  14. Gasport

    Gasport Bit poster

    Messages:
    6
    I have a similar problem.

    I connected a WD Mybook to my iMac via a powered USB Hub. The iMac recoginzed the drive and I formattted it in FAT 32. I then Installed Parallels (Current Version) and the Vista Upgrade. I first tried a USB flash drive and Vista recognises that without any problem. I then connected the WD to the HUB again and Vista recognised this and installed the drivers. I checked the Device Manager and it shows the 2 Mass Storage Devices attached. All this being said, the WD USB hard drive does not show in Explorer. It only shows the USB Flash Drive. I do have external HDD checked in Parallels and even set it to AutoConnect ON and still the drive does not show.

    I can connect to my PC and the external hard drives attached to that as well as a NAS Drive on my network.

    Any suggestions?
     

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