Just think of it as a large disk. That is how the LVM layer is supposed to work. The programs are not supposed to be aware of it.
For instance, normally you have:
1) Physical Hard Drives ( hda, hdb, ... )
2) Partitions (hda1, hda2, .... )
3) File system format (ext, xfs, jfs, .... )
Amule should not even be aware of the file system that it is on or the partition type like most programs (Except for high performance databases that sometimes use there own filesystem formate so they operate at level 2). That is the beauty of linux and the file system. It should just say output to so and so file and then the kernel or other programs handle the traslation to the disk data.
LVM adds a layer into that mix:
1) Physical Hard Drives ( hda, hdb, ... )
2) Volume Groups ( /dev/vg, /dev/vg1, ... ) - Think of these as virtual hard disks
3) Logical Volume ( /dev/vg/usr, /dev/vg/whatever, .... ) - Think of these as partitions
4) File system format (ext, xfs, jfs, .... )
The advantage of LVM is that it is all dynamic now. You can resize partitions and volume groups on the fly to meet whatever your demands are. I hope this was not over the top, but the quick answer is since amule can operate on any file system that Linux supports because it is not aware of the file system. It should not matter that it is on a LVM2 group. Otherwise you would have to have a different version of amule for each filesystem type and would destroy portability
PS - Love the sig
