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NFS

Network File System

  • NFS v3 only use IP address / host name to verify client
  • NFS v4 support IP address / Kerberos (verification / hash / encryption)

See also

  • iSCSI

NFS server​

Ubuntu

sudo apt update
sudo apt install nfs-kernel-server

RHEL

sudo yum install nfs-utils

Config​

/etc/exports
# <path>  <host>(<options>)  ...
/srv/nfs  10.0.0.2(rw,sync,no_subtree_check,insecure)  10.0.1.0/24(rw,sync,no_subtree_check,insecure)
OptionDescription
rwallow read and write
syncreply after the change is committed (slower, safer)
asyncreply before the change is committed (faster, corrupted when unclean)
no_subtree_checkdisable subtree check (less issue)
insecureallow network port ≥ 1024

Reload / Update exports​

exportfs -rv
-rre-export all directories
-vverbose

Show exported NFS​

# showmount { -e | --exports }
showmount -e

NFS client​

Ubuntu

sudo apt update
sudo apt install nfs-common

RHEL

yum install nfs-utils

Show NFS server exports​

Run on client host

# showmount { -e | --exports } <host>
showmount -e 10.0.0.1

mount NFS​

NFS options ref: man nfs

# mount [-vv] -t nfs <host>:<path> <path>
mount -t nfs 10.0.0.1:/srv/nfs /mnt/nfs

# NFS v3
mount -t nfs -o vers=3 10.0.0.1:/srv/nfs /mnt/nfs

Auto mount at boot​

  • option auto: auto mount when mount -a (at boot time)
  • defaults included auto option
/etc/fstab
# <file system>  <mount point>  <type>  <options>  <dump>  <pass>
10.0.0.1:/srv/nfs  /mnt/nfs  nfs  defaults  0  0

# NFS v3
10.0.0.1:/srv/nfs  /mnt/nfs  nfs  defaults,vers=3  0  0

Troubleshot​

Permission denied

  • Use mount with verbose option for debug

    mount -vvvv ...

  • Check if IP address is match

  • If using NFSv4, try add sec=sys option to client and server

    • NFSv4.0 client connect to NFSv4.2 server need add option sec=sys