This fixed my problem with a missing USB pen drive
Thank-you - finally you have solved this very annoying problem and I can access my USB pen drive volume directly from the desktop again. This is definitely a side effect of using Parallels Desktop as that software sets the "invisibility" of USB drives when they are in use by Parallels. Sometimes it seems to get stuck in the invisible state, so this fix just makes them visible again.
The short version of the fix is below - thanks again
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(From the terminal; if you're not comfortable with the terminal then use the link above which shows you how to do it using the GUI):
cd /Developer/Tools
./GetFileInfo /Volumes/<yourdrive>/
directory: "/Volumes/<yourdrive>"
attributes: aVbstclinmedz <--- note the "V" = invisible drive
created: 01/01/1904 00:00:00
modified: 05/09/2008 23:34:14
./SetFile -a v /Volumes/<yourdrive>/
./GetFileInfo /Volumes/<yourdrive>/
directory: "/Volumes/<yourdrive>"
attributes: avbstclinmedz <--- note the "v" = visible drive
created: 01/01/1904 00:00:00
modified: 05/09/2008 23:34:14
Force quit Finder.app and <yourdrive> will reappear on the desktop.
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For anyone else having this trouble, let's put a few keywords in here to allow them to find this thread (I had trouble googling this issue): parallels vmware desktop usb pen drive volume finder invisible does not appear cannot be seen see missing invisible visible lost mac hidden vanished vanishing disk utility diskutility /volumes mount unmount eject