ls -la /dev/mapper/*
crw------- 1 root root 10, 59 2011-04-06 17:01 /dev/mapper/control
lrwxrwxrwx 1 root root      7 2011-04-06 17:01 /dev/mapper/lvmlen-root -> ../dm-1
lrwxrwxrwx 1 root root      7 2011-04-06 17:01 /dev/mapper/lvmlen-swap -> ../dm-2
lrwxrwxrwx 1 root root      7 2011-04-06 17:01 /dev/mapper/sda8_crypt -> ../dm-0


sudo dmsetup ls
sda8_crypt	(252, 0)
lvmlen-swap	(252, 2)
lvmlen-root	(252, 1)