Setting up an NFS server

2025-11-03T00:23:41Z

Camelia: Remove duplicate "in the"

This page documents configuring Network File System (NFS) on both server and client side including autofs and Kerberos authentication.

== Installation ==

Install the following package for both NFS client and NFS server service. {{Cmd|# apk add nfs-utils}}

== Configuration ==

Setting up NFS service on Alpine Linux is no different from other Linux distributions.

=== NFS server ===

Setup export dirs in {{Path|/etc/exports}} on your server with IP address 10.10.10.1. For example: {{Cat|/etc/exports|<nowiki>/data 10.10.10.0/24(rw,nohide,no_subtree_check,no_root_squash)
</nowiki>}}

After editing {{Path|/etc/exports}}, reload your setting: {{Cmd|# exportfs -afv}}

To make NFS server service to autostart on boot: {{Cmd|# rc-update add nfs}}

To start NFS server service now: {{Cmd|# rc-service nfs start}}

NFS server configuration file is located in {{Path|/etc/conf.d/nfs}}.

==== NFS version ====

To configure nfs version in use, pass appropriate options to nfsd in {{Path|/etc/conf.d/nfs}}. For example: {{Cat|/etc/conf.d/nfs|<nowiki># Options to pass to rpc.nfsd
# `-N 3` means version 3 is disabled
OPTS_RPC_NFSD="8 -N 3"
</nowiki>}}

After editing {{Path|/etc/conf.d/nfs}}, restart the server: {{Cmd|# rc-service nfs restart}}

{{Todo|NFS v4 doesn't need rpcbind. Disabling it with command {{ic|chmod 444 /etc/init.d/rpcbind}} breaks nfs service. Help add the correct method to disable rpcbind.}}
=== NFS client ===

To mount NFS shares automatically, an entry needs to made to {{Path|/etc/fstab}} as follows:{{Cat|/etc/fstab|10.10.10.1:/data /mount/point nfs4 rw,_netdev 0 0}}

To mount nfs share from {{Path|/etc/fstab}} file at booting of the system:{{Cmd|# rc-update add nfsmount}}
To mount the nfs shares from /etc/fstab file now:{{Cmd|# rc-service nfsmount start}}

You can check your boot services:{{Cmd|# rc-status}}

{{Tip| netmount is a general service for all network-based filesystems, while nfsmount is specifically tailored for NFS.}}
To use netmount, here are the equivalent commands:{{Cmd|<nowiki># rc-service netmount start
# rc-update add netmount</nowiki>}}

== Using autofs ==

[https://docs.kernel.org/filesystems/autofs.html Autofs] is another alternative for mounting filesystems like NFS. Autofs aims to provide on-demand mounting and race free automatic unmounting of various other filesystems.

Ensure that {{pkg|autofs}} package is installed, if not installed already. {{Cmd|apk add autofs}}
Add an entry in the file {{Path|/etc/auto.master}} that points to a map file to define the mount points for the {{ic|/mnt/nfs}} directory.. For example:{{Cat|/etc/auto.master|<nowiki>/mnt/nfs /etc/auto.nfs --timeout=60</nowiki>}}
Create the Map File {{Path|/etc/auto.nfs}} that maps the NFS share {{ic|10.10.10.1:/data}} to {{ic|/mnt/nfs/share}} as follows:{{Cat|/etc/auto.nfs|share -rw 10.10.10.1:/data}}
Start and Enable autofs:{{Cmd|<nowiki># rc-update add autofs
# rc-service autofs start</nowiki>}}

Eventhough autofs is primarily a client-side tool it can also be used on servers for dynamic mounting if required. For an use case of using Autofs on servers, refer to [[Raspberry_Pi_4_-_Persistent_system_acting_as_a_NAS_and_Time_Machine#Adding_and_Sharing_a_Disk|Sharing a Disk]] page.

== Kerberos authentication ==

By default, NFS security only validates the IP of the client. You can add user level authentication with a Kerberos authentication protocol. The choices are:
* [https://web.mit.edu/kerberos/www/ MIT KRB5] available in {{pkg|krb5}} package
* [https://github.com/heimdal/ Heimdal] available in {{pkg|heimdal}} package

{{Note|It is recommended to have the same Kerberos flavor across the network as both implementations are not completely mutually compatible.}}

The example given below uses MIT KRB5 syntax. So install the server package {{pkg|krb5-server}} on server and {{pkg|krb5}} package for client machines.

=== Server configuration ===

Assuming you setup Kerberos in the network, create ticket to your NFS machine :

{{Cmd|# kadmin: addprinc -randkey nfs/nfs1.example.com@EXAMPLE.COM}}

And add it to the machines krb5.keytab file:
{{Cmd|# kadmin: ktadd nfs/nfs1.example.com@EXAMPLE.COM}}

Then, edit your {{Path|/etc/exports}}, and add sec=krb5 (only authentication), sec=krb5i (also hmac signing) or sec=krb5p (also encryption). For example:

{{Cat|/etc/exports|<nowiki>/data 10.10.10.0/24(rw,nohide,no_subtree_check,sec=krb5p,no_root_squash)
</nowiki>}}

After editing {{Path|/etc/exports}}, reload your setting
{{Cmd|# exportfs -afv}}

User id mapping is managed by <code>nfsidmap</code> utility from {{pkg|nfs-utils}} package.

=== Client configuration ===

In order for the client to connect to NFS via kerberos, enable and start rpc.gssd service.
{{Cmd|# rc-update add rpc.gssd}}
{{Cmd|# rc-service rpc.gssd start}}

== See also ==

* [https://wiki.archlinux.org/title/NFS NFS in Arch wiki]
* [https://wiki.gentoo.org/wiki/Nfs-utils NFS in Gentoo Wiki]
* [https://wiki.debian.org/NFSServerSetup#NFSv4_only NFS Server Setup in Debian wiki]
* [[Raspberry_Pi_4_-_Persistent_system_acting_as_a_NAS_and_Time_Machine]]
* [https://www.willowbarraco.fr/my-perfect-music-synchronization-solution/ NFS and FS-cache based synchronization solution ]
[[Category:Server]]

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Setting up an NFS server