I don't understand mountpoint - LVM2-mapping

[LesPaul]

Since Fedora10 I have the following question and I wonder if there are others with the same 'problem' or are there people who can explain why/how it works? It has to do with translation from logical volume to mountpoint from the file system via /dev/dm-X:
/dev/VolGroup00/LogVol00 -> /dev/dm-0 -> /home

This is the matter:
I use LVM2 and created a physical volume as follows:
--- Physical volume ---
PV Name /dev/sda2
VG Name VolGroup00

In this volume I created 4 logical volumes:
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
and so on.

In my fstab of when I type mount I see:
/dev/dm-0 on / type ext3 (rw)
/proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sda1 on /boot type ext3 (rw)
/dev/dm-2 on /home type ext3 (rw)
/dev/dm-1 on /var type ext3 (rw) I don't understand mountpoint - LVM2-mapping

As I type: lvdisplay /dev/VolGroup00/LogVol00 is see:
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID 3Erzk2-myjc-cb8T-90ch-EAE6-lMIA-aqVqn2
LV Write Access read/write
LV Status available
# open 1
LV Size 1,94 GB
Current LE 62
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:3

Here is the question (what I don't get):
Where can I retrieve the link between the given LVM-names (/dev/VolGroup00/LogVol0X) and the spontanious given names like /dev/dm-X?

My gnome LVM-manager tells me the volumes are NOT mounted at all.

Then: Grub boots ok with kernel 2.6.27.19 as it points to root=/dev/VolGroup/LogVol01, but not with 2.6.27.21, as it points to root=/dev/dm-0.
The error at booting is: unable to access resume device, could not mount filesystem /dev/root.
As I replace the mountpoint in root=/dev/VolGroup/LogVol01, the error remains except for the filesystem. Now it complains about missing /dev/dm-3 (is the swap partition).

Anyone? I'm stuck/lost...