External Hard Drive Problems

Discussion in 'Parallels Desktop for Mac' started by Phi3nD, Oct 11, 2006.

  1. Phi3nD

    Phi3nD

    Messages:
    3
    I'm still having problems getting my external usb hard drive to work in new Parallels- 1922 in Windows XP. Did they not yet fix this problem or am I just having problems? I loaded the Maxtor CD and it recognizes and shows that new hardware is found,but never detects the drive.
     
  2. joem

    joem

    Messages:
    1,247
    External hard drives are currently unsupported.
    You can put an emulated hard drive (.hdd file) on any mounted local volume though, so you can use the drive for guest storage.
     
  3. dm3

    dm3

    Messages:
    46
    Are you serious?
    Parallels doesn't support using an external hard drive? They also don't support having the .hdd file on a network share either.

    So there is no option if you run out of space on your local drive. This is serious problem.

    Why does it not work? Is there some special caching policy that they use in Mac OS that isn't support except on a local drive? Can't they turn it off or make it an option?

    What you do you mean, you can use the drive for "guest" storage?
     
  4. Paul Linden

    Paul Linden

    Messages:
    76
    I have all my Parallels VMs on an external drive. What I did was move ~/Library/Parallels to the external drive. Works fine. Perhaps support for this could be a better within Parallels, but the amount of work I needed to do was minimal.

    This also makes the VMs available to other users with the correct permissions.

    As for network drives - if you can mount the drive in OS X you can store the VMs there. You can select where on the file system or external drive or network drive to open a VM from.

    Actually mounting external drives from within the guest OS is not yet supported, but from your second post, it looks like you don't need to do that.

    If you need extra HD space on your VM, you can add up to three new virtual drives and format them the same way you would do on a real machine running Windows or whatever OS you're using. You can store this virtual drive anywhere on your Mac or external drive or network drive and just point the VM configuration to that location. It will show up looking like an internal drive in Windows as probably drive E: etc, and in Linux as /dev/sdbX
     
    Last edited: Oct 13, 2006
  5. dm3

    dm3

    Messages:
    46
    Not true. If you put a .hdd file on a network share that is mounted by Mac OS, Parallels will refuse to boot from that image giving an error "unable to determine drive geometry".

    Are you saying that there is some way around this? What does the symlink have to do with anything?
     
  6. Paul Linden

    Paul Linden

    Messages:
    76
    remove reference to symlink

    Don't mount using samba. Mount using :
    sudo mount -o -P network_drive:/parallels_directory ~/mount_point

    You'll also need r/w permissions on the directory on the external drive.

    This works fine with me.
     
    Last edited: Oct 13, 2006
  7. dm3

    dm3

    Messages:
    46
    I still don't follow. I have space on a Windows machine that I tried mounting using samba, ie
    mount_smbfs //host/c$ ~/mountpoint
    I copied the .hdd file on there and tried to have Parallels use it and it fails complaining that it can't determine drive geometry. Someone else reported the same problem and Parallels support says that they don't support booting from a .hdd on a network share. I've asked support for more clarification but they have not responded.

    I don't understand the mount command you specified. I can't find a man page that describes a -P option. What does "network_drive" mean? When mounting from a Windows machine (samba), you need to specify the host and resource on the host that you're mounting. Is this an alternative way to perform a samba mount or are you describing something totally different.

    I asked about the symlink because I haven't been able to get this to work, yet you say that it does work and I'm struggling to decipher that the critical difference is.
     
  8. joem

    joem

    Messages:
    1,247
    A mounted external drive is local. You can put virtual machines on any mounted local drive including firewire and USB, but not network drives which are network, not local.

    The guest can't directly use the drive as a raw drive or directly access files on a native (non .hdd) partition.

    Sorry if I wasn't clear enough.
     
  9. Paul Linden

    Paul Linden

    Messages:
    76
    Don't use samba. I believe that's what I said in the first sentence of my last post. You need to use NFS. It seems Parallels doesn't support samba mounted drives, but nfs mounts work fine.

    I use Linux and I forget that others don't. I'm able to boot my Parallels VMs from an nfs mount that's on a Linux machine. (I can do it but I actually use an external drive). I don't think NFS comes with Windows by default - it should come with "Windows Services for Unix" downloadable from http://www.microsoft.com/downloads/...88-601b-44f1-81a4-02878ff11778&DisplayLang=en

    I don't have a Windows machine on my network at the moment (thank god) so I can't test if that works. I really don't understand why anyone would want to use Windows for a network file server, since Linux is so much easier to set up and use out of the box (for servers).

    -P is a mount_nfs option that forces mount_nfs to use a port < 1024 for mounting. OS X tries to use > 1024 but Linux requires < 1024.

    The syntax of the mount command is simple but slightly different - like with samba, you mount on a host:
    sudo mount -o -P host:/parallels_directory ~/mount_point

    This is the same as:
    sudo mount_nfs -o -P host:/parallels_directory ~/mount_point

    I'm sorry if writing "network_drive" rather than "host" confused you.

    I''m removing all references to symlink from my previous posts since it seems to have caused more confusion.
     
  10. dm3

    dm3

    Messages:
    46
    Saying that it was an NFS mount was the key.
    I installed Windows Services for Unix and tried it and amazingly it works! Thanks! I can finally offload big .hdd files. I'm using a Windows machine as a file server because I no longer need it for anything else since I'm now doing everything on the Macbook.
    I didn't need to use sudo nor the -P option, a simple mount_nfs command worked.
    I have a gigabit ethernet crossover cable between the Macbook and the Windows PC. I'm surprised how poor the throughput is that I get between the systems, especially using NFS. I think its the PC's gigabit ethernet card, but I may try running Ubuntu and see if I get better throughput. After tweeking settings I can get up to 11MB/sec, but I've achieved 25MB/sec to another laptop running Windows XP and using Samba.
     
  11. joem

    joem

    Messages:
    1,247
    The man page for mount_nfs has some tuning comments that may help.
     

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