repairing a virtual disk (using cmd line question)

i'm trying to perform a repair of my virtual disk using the command line:

vmware-vdiskmanager -R virtual_disk.vmdk

following the steps in step 3 here: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1008485

i keep my virtual machine on a drive seperate from where my workstation is installed, so i don't know the correct argument/syntax to use. when i use:

vmware-vdiskmanager -R V:\Windows 8-000002.vmdk

i get a 'diskname or some other argument is missing'.

does anyone know how this cmd line should read?

thanks!

bobby