See the following referenced resources at My Oracle Support (login required):

• Doc ID 1286796.1: rp_filter for multiple private interconnects and Linux Kernel 2.6.32+.Doc ID 359515.1: Mount Options for Oracle files for RAC databases and Clusterware when used with NFS on NAS devices
• Doc ID 1620238.1: Creating File Devices On NAS/NFS FileSystems For ASM Diskgroups
• Doc ID 1003375.1: NFS-Filesystems: Hard vs Soft mounts Explained
• Doc ID 762374.1: Step by Step - Configure Direct NFS Client (DNFS) on Linux
• Doc ID 1601897.1: ASM Certification On Thin-Provisioned NFS Files
• Doc ID 731775.1: How To Create ASM Diskgroups using NFS/NAS Files?
• Doc ID 1164673.1: NFS Performance Decline Introduced by Mount Option "actimeo=0
• Doc ID 397194.1: How to Optimize NFS Performance with NFS options
• Doc ID 1552831.1: How to Configure DNFS to Use Multiple IPs
• Doc ID 1902001.1: What is ASM rebalance compact Phase and how it can be disabled
• Doc ID 604683.1: Supported Backup, Restore and Recovery Operations using Third Party Snapshot Technologies
• Doc ID 221779.1: How to prepare the Oracle database for Snapshot Technologies and ensure a consistent recovery
• Doc ID 822481.1: How to Setup Direct NFS Client Multipaths in Same Subnet
• Doc ID 2323931.1: Is It Possible To Configure 2-factor Or Multi Factor Authentication For Oracle DBA Accounts?
• Doc ID 2108714.1: RMAN backup types that require “NOAC” on NFS Mount Points
• Doc ID 397194.1: How to Optimize NFS Performance with NFS options.