Patching a 2-node 11.2.0.3 cluster, one node at a time ..

Need to apply a PSU to a 2-node 11.2.0.3 cluster on RHEL, one node at a time.

I have a 2-node 11.2.0.3 Cluster.  Grid home and DB homes are NOT on shared disk.  but, I have an ACFS mount, that is mounted on both the nodes.

can i apply opatch using "opatch auto .."   on each node ? do this on node1 first, then when all are service are up (after patching taht node), move to node2 and run the same command ?

OR, do i have to unmount ACFS volumes before applying the patch ?

thanks,