Find mapping of ASM disks to Physical Devices

Query asmdisk to get the major - minor numbers

$ /etc/init.d/oracleasm querydisk -d OCRVOTED04
Disk "OCRVOTED04" is a valid ASM disk on device [253, 27]

Match the number to physical device

$ ls -l /dev|grep 253|grep 27
brw-rw----  1 root root     253,    27 Jun  2 00:50 dm-27