What you are seeing are called "Lunz" devices. Basically placeholders for paths to the array. Primus emc170849 and emc65060 explain about them and what your options are.  -Ryan
I have a backup proxy server that I present all my VMware LUNs to so that I can utililize the SAN for backups.  I removed a LUN today that happened to have LUN ID 0.  The disk showed up in Disk Management (Windows Server 2003) as unknown/unreadable.  I could not get rid of it.  I added a different LUN to the storage group and it grabbed ID 0.  The unknown/unreadable disks vanished.  Based off a little reading, it seems like it's related host ID 0.  So, my question is:  If I wanted to remove a LUN permenantly that was assigned ID 0 and not replace it with anything, how would I do this without the disk show up as unknown/unreadable??
Removing a LUN and Host ID Zero