Solution: Parallels 9 under Yosemite breaks OS X access to Windows drives

Problem: Parallels 9 under Yosemite breaks OS X access to Windows drives

Key Phrases: Access Windows drives from OS X under Parallels

The following isn't the best solution to this problem, but it works, and others may find it helpful until/unless someone at Parallels fixes the underlying problem or identifies the offending configuration setting that can be changed to fix it.

Specifics:

My wife was running Win 7 SP 1 under Parallels Desktop 9.0.24251 under Mavericks, OS X 10.9.x. I back up her Windows data files to an external drive on my own Mac by running an OS X bash script on her Mac that mounts my drive over a WiFi net, then creates a single tar file on my external drive from her Windows files, accessing her Windows files through .../Library/Parallels/winxp.pvm/Windows Disks/K, which links to /Volumes/K ('K:' being her personal virtual drive under Parallels) [and the winxp folder name is a carryover from when it was an WinXP machine; it's Win 7 now]. That virtual mount point was created by Parallels and provided an easy path from OS X to her Windows drives.

She had a problem with iPhoto that I thought would be resolved by upgrading to Yosemite, with the accompanying iPhoto upgrade (I was wrong, but not relevant here except that it caused this problem).

Once I upgraded to Yosemite, the mounted Windows volumes were absent under OS X /Volumes. The links to them were still there under .../Library/Parallels/winxp.pvm/Windows Disks/, but, of course, they linked to nothing.

So the nightly backups failed.

I checked Parallels support site and found some suggestions. I uninstalled and re-installed Parallels Tools a couple of times. I reviewed my virtual machine configuration, but my settings appear to be correct. The Windows app folder appears on the OS X toolbar, for example, and the Parallels Tools Windows processes to support integration are running, as far as I can tell (though I found no specific references to virtual mount points under OS X).

I searched the web (Parallels forums/Desktop for Mac/Windows Guest OS, Deja News, Google) and found no solution. In fact, I found only one reference [Alex_Newman, 23 Oct 2014] that suggested that anyone else had the problem, causing me to wonder if this was an undocumented (and unsupported) feature of Parallels that only a couple of us had used.

I posted a followup note to the one problem report I saw on Parallels forums, but there were no responses.

So I tried an alternate solution, and it works. Here it is for anyone facing the same problem.

Solution:

Offer the target Windows drive as a network service to OS X, then mount that service under OS X as a virtual mount point under /Volumes.

To offer the Windows drive as a network service, here?s a solution (this works; other approaches may be better):
Click the Windows 7 start button (globe)
Click 'computer' on right panel
Right click the drive you want to offer as a service to OS X
Click the 'sharing' tab
Click 'Advanced Sharing'; you'll need admin privs to proceed
Click the 'Share this folder' box to enable sharing
Exit out ('OK') of the drive popups
On the left side of the 'Computer Panel', look for the server name
('KLT-WIN7' in my case); the drive you want to share will be listed

To mount the service under OS X, either: go to the OS X Finder, look for 'Shared' in the left panel, find the Windows service you're looking for, double click (you may need to authenticate to the Windows account), and you'll see that drive as a folder; or, from the command line in OS X,
mkdir MyWinDrive
/sbin/mount_smbfs //usernameassword@MyWinHost/DriveLetter MyWinDrive
where
username = your user name on your Windows virtual machine
password = the password for that username on your Win VM
MyWinHost = the name of your Windows server
DriveLetter = the identifier for the Windows drive you shared from Windows


Using this approach, the backup that used to take 7 minutes for a 7GB tar file now takes 13 minutes. But it works.

Good luck! I'll watch this thread for a while in case anyone trying this has problems. I don't have Parallels on my own Mac but can check things on my wife's laptop if there are questions.