Add to this a search in /var/log/udev:
root@malorent:~# grep mapper /var/log/udev KERNEL[1272027429.282338] add /devices/virtual/misc/device-mapper (misc) DEVPATH=/devices/virtual/misc/device-mapper DEVNAME=mapper/control UDEV [1272027429.914560] add /devices/virtual/misc/device-mapper (misc) DEVPATH=/devices/virtual/misc/device-mapper DEVNAME=/dev/mapper/control DEVNAME=/dev/mapper/HEBEX-WOO_LOG FSTAB_NAME=/dev/mapper/HEBEX-WOO_LOG DEVNAME=/dev/mapper/HEBEX-WOO FSTAB_NAME=/dev/mapper/HEBEX-WOO DEVNAME=/dev/mapper/HEBEX-WOO_PROG FSTAB_NAME=/dev/mapper/HEBEX-WOO_PROG DEVNAME=/dev/mapper/HEBEX-VAR_LOG FSTAB_NAME=/dev/mapper/HEBEX-VAR_LOG
Add to this a search in /var/log/udev:
root@malorent:~# grep mapper /var/log/udev 1272027429. 282338] add /devices/ virtual/ misc/device- mapper (misc) /devices/ virtual/ misc/device- mapper mapper/ control virtual/ misc/device- mapper (misc) /devices/ virtual/ misc/device- mapper /dev/mapper/ control /dev/mapper/ HEBEX-WOO_ LOG /dev/mapper/ HEBEX-WOO_ LOG /dev/mapper/ HEBEX-WOO /dev/mapper/ HEBEX-WOO /dev/mapper/ HEBEX-WOO_ PROG /dev/mapper/ HEBEX-WOO_ PROG /dev/mapper/ HEBEX-VAR_ LOG /dev/mapper/ HEBEX-VAR_ LOG
KERNEL[
DEVPATH=
DEVNAME=
UDEV [1272027429.914560] add /devices/
DEVPATH=
DEVNAME=
DEVNAME=
FSTAB_NAME=
DEVNAME=
FSTAB_NAME=
DEVNAME=
FSTAB_NAME=
DEVNAME=
FSTAB_NAME=