[CentOS] Mounting a LVM partition on a USB attached drive

I have one of those USB hard drive cases, and I have my old hard drive 
in it.

Eventhough I have made the changes to mount multiple USB drives in one 
USB device (works fine for my media play with internal and SD drive), I 
am only getting the first partition (/Boot (2)) automounted.

df does not show anything more about the drive, but the gnome hardware 
browser shows all three partitions on the drive:

/dev/sda
    sda1      ext3
    sda2      linux-swap
    sda3      LVM Physical Volume

Naturally it is sda3 that I want to access.

So far my google searches have come up empty.