Technical Report NFS in NetApp ONTAP Best practices and implementation guide Justin Parisi, NetApp July 2021 | TR-4067 Abstract This document provides basic concepts, support information, configuration tips, and best practices for NFS in NetApp® ONTAP®. This guide covers the latest available ONTAP versions for currency and length. In most cases, the commands and best practices listed in this guide apply to all ONTAP versions. Results might vary in older ONTAP versions. Consult the product documentation for your ONTAP version when necessary. TABLE OF CONTENTS Basic NFS concepts in NetApp ONTAP .................................................................................................... 7 Intended audience and assumptions .......................................................................................................................7 Stated support for NFS ............................................................................................................................................7 NFS features ...........................................................................................................................................................8 NFS server options ..................................................................................................................................................9 Namespace concepts ............................................................................................................................................ 11 File locking concepts ............................................................................................................................................. 20 Export concepts ..................................................................................................................................................... 23 The anon user ....................................................................................................................................................... 29 The root user ......................................................................................................................................................... 29 Limiting access to the SVM root volume ................................................................................................................ 30 Mapping all UIDs to a single UID (squash_all) ...................................................................................................... 32 Special character considerations ........................................................................................................................... 33 NFS version considerations .................................................................................................................... 34 NFSv2 considerations ........................................................................................................................................... 34 NFSv3 considerations ........................................................................................................................................... 34 NFSv4.x considerations ......................................................................................................................................... 39 NFSv4.0 ................................................................................................................................................................ 42 NFSv4.1 ................................................................................................................................................................ 52 NFSv4.2 ................................................................................................................................................................ 56 Name services ........................................................................................................................................... 57 DNS 57 Identity management name services ..................................................................................................................... 58 Local files .............................................................................................................................................................. 59 Multiprotocol NAS ..................................................................................................................................... 61 Qtrees ......................................................................................................................................................... 61 Qtrees and file moves ............................................................................................................................................ 61 Qtree IDs and rename behavior ............................................................................................................................ 61 File handle effect for qtree exports ........................................................................................................................ 62 Mounting multiple Qtrees in the same volume on the same NFS client ................................................................. 62 Subdirectory exports .............................................................................................................................................. 63 User and group owners ......................................................................................................................................... 63 Nondisruptive operations with NFS ........................................................................................................ 63 2 NFS in NetApp ONTAP: Best practices and implementation guide © 2021 NetApp, Inc. All Rights Reserved. Replay/reply cache ................................................................................................................................................ 64 File locking............................................................................................................................................................. 64 Impact of NFSv4.x locks on failover scenarios ...................................................................................................... 65 Difference between grace seconds and lease seconds ......................................................................................... 66 NFSv4.1 sessions .................................................................................................................................................. 66 What happens during LIF migrations in NFSv4.x? ................................................................................................ 66 LIF migrations with NFSv3..................................................................................................................................... 66 Safely decommissioning data LIFs in use with NFS .............................................................................................. 67 pNFS and LIF outages .......................................................................................................................................... 68 Wdelay/No_wdelay ................................................................................................................................................ 68 Direct connect NFS ............................................................................................................................................... 68 Choosing volume styles: FlexGroup or FlexVol? ................................................................................. 69 NFS auditing .............................................................................................................................................. 69 NFS audit setup ..................................................................................................................................................... 69 NFS best practices .................................................................................................................................... 70 General ONTAP best practices ............................................................................................................................. 70 ONTAP data LIF best practices with NFS environments ....................................................................................... 71 NFS security best practices ................................................................................................................................... 75 Name services best practices ................................................................................................................................ 80 NFS client best practices ....................................................................................................................................... 80 Logging, monitoring, and statistics ........................................................................................................ 88 Advanced NFS concepts .......................................................................................................................... 93 Umask ................................................................................................................................................................... 93 NFS user nfsnobody .............................................................................................................................................