In 12c, Oracle introduced a new feature ASM Filter Driver (AFD) which is a replacement for Oracle ASMLIB. We still have the option to use Oracle ASMLIB if you choose to.
IMO, AFD is superior to ASMLIB and here is why:
- Oracle AFD ships with Oracle Grid, no need for extra download. You don’t have to do an initial configuration either like with ASMLIB (oracleasm configure)
- We adding disks on 1 node, there is no need to scandisk on other nodes
- When you add a disk to AFD, it protects the disk against any OS mistakes like fdisk, mkfs and even dd commands, now how cool is that