Question: what is acfs and how to configure in rac?
Answer: Create an ASM DISKGROUP( ON NODE 1) ... 
Mount the diskgroup from other nodes(On NODE 2) ... 
check the diskgroup status( from any node) ... 
Create a new ADVM volume in the diskgroup(ACFSPOC):(ON NODE 1) ... 
create mount point with proper permission on both nodes: ... 
Start the ACFS file system resource:( on node 1 from the root)