Oracle ASM Filter Driver (Oracle ASMFD) maintains storage file path persistence and helps to protect files from accidental overwrites.

• About Oracle ASM with Oracle ASM Filter Driver
  During Oracle Grid Infrastructure installation, you can choose to install and configure Oracle Automatic Storage Management Filter Driver (Oracle ASMFD). Oracle ASMFD helps prevent corruption in Oracle ASM disks and files within the disk group.
• Configuring Oracle ASM Filter Driver
  You can configure Oracle ASM Filter Driver (Oracle ASMFD) for device persistence during the installation of Oracle Grid Infrastructure or after Oracle Grid Infrastructure has been installed.
• Migrating Oracle ASM Disk Groups From ASMLIB to Oracle ASM Filter Driver
  Follow this procedure to migrate Oracle ASM disk groups to Oracle ASMFD in an Oracle Grid Infrastructure for a standalone server environment.
• Determining If Oracle ASM Filter Driver Is Configured
  The value of the AFD_STATE parameter of SYS_ASMFD_PROPERTIES specifies whether Oracle ASMFD is configured for the Oracle ASM instance.