All ASMLib installations require the oracleasmlib and oracleasm-support packages. The oracleasm kernel driver is included in the Oracle UEK kernel. Perhaps you are missing the oracleasmlib package. You can download it from:
Oracleasmlib is not necessary for ASM to work, but it contains software necessary for Linux oracleasm, including the /usr/sbin/oracleasm-discover utility, which the Oracle installer used in the previous 11g version to detect available ASM volumes.
I have both packages installed (oracleasm-support & oracleasmlib) along with kernel 2.6.39-400.109.5.el6uek.x86_64.
Been told this morning that I must install something called "Oracle grid infrastructure" in order to use ASM before installing the database software.
This is crazy to me because I have already used the packages mentioned above to create a ASM drive.
Oracle ASMLib takes care of device management on the OS side, such as device naming, scanning and preparing disks for ASM use. In order to have any database use ASM, you must install and setup a Oracle ASM instance. Other databases will then connect to the ASM instance to access ASM disk groups.