Renaming ML install partition on USB disk

I've created a Mountain Lion install disk on a partition on an external USB disk which also has a Lion installer.

Both appeared as Mac OS X Install ESD when mounted in Finder, but I renamed them and this rename persists across unmount/remount.

However, when I reboot holding down the Option key to select the volume to boot from, both of these partitions appear as just Mac OS X so, other than booting from one, I don't know which is which.

From this, I take it that in Finder it is just the mount point (in /Volumes) that has been renamed, not the partition name on the disk?

Is there anyway to rename the actual partition name on the disk?

pujols617 said:

I did exactly the same as you and I'm wondering the same. Does anyone know the answer to this?

Click to expand...

I also posted on Apple's Support Forums and someone suggested changing the icon - they even supplied some cool icons - which I did and it works. Link to thread