wd passport could not unmount disk for repair

If you have one, try plugging it in so the drive is not reliant upon bus power. Some external drives come with optional power adaptors (especially smaller and more portable drives). You can also try this when booted into Safe Mode, to see if any third-party plug-ins or nonessential features of OS X are contributing to the problem. Try each USB or FireWire port available on your system (use FireWire 400/800 adaptors or conversion cables if necessary) to see if that helps. Sometimes there are differences in the USB ports on the system, which result in power or speed differences that can result in external devices not being recognized properly. Press the Option key and right-click the Finder icon in the Dock, and choose 'Relaunch'. The discs may be mounted and available however, if the Finder is having troubles displaying them then it may appear as though the discs are not mounted. If this happens, there are several things you can try:

It may make whirring sounds as the device powers up, but will not display in the Finder.

If you use external USB or FireWire hard drives on your Mac, one problem you may encounter is where the drive will not mount in OS X when attached to your computer.

Wd passport could not unmount disk for repair