Home NFS Setup HOWTO
This is a quick guide to setting up NFS in Slackware for use in a home LAN. The example used is for connection of a laptop computer with a desktop computer that also has an NTFS partition mounted on /music. It assumes that basic network connectivity has been established. This guide is largely cut and pasted from other more definitive documents.
2.1. What is NFS? The Network File System (NFS) was developed to allow machines to mount a disk partition on a remote machine as if it were a local disk. It allows for fast, seamless sharing of files across a network. It also gives the potential for unwanted people to access your hard drive over the network (and thereby possibly read your email and delete all your files as well as break into your system) if you set it up incorrectly.
Setting up a secure NFS does require some additional work, but as good security habits start at home, these steps will also be presented.
For the purposes of this example:
- the desktop computer will be called DESKTOP and has an IP address 10.1.1.2
- the laptop computer will be called LAPTOP and has an IP address 10.1.1.3 using a wired connection
- or the laptop computer will be called LAPTOP-W and has an IP address 10.1.1.4 using a wireless connection
Both computers will be setup to act as NFS servers as well as clients.
Important files -
On the desktop computer /etc/hosts should have lines like
10.1.1.3 LAPTOP.<your domain> LAPTOP 10.1.1.4 LAPTOP-W.<your domain> LAPTOP-W
On the laptop computer /etc/hosts should have a line like
10.1.1.2 DESKTOP.<your domain> DESKTOP
On both machines add
portmap:ALL lockd:ALL mountd:ALL rquotad:ALL statd:ALL
On the desktop computer add
# For NFS mount from LAN portmap: 10.1.1.3 , 10.1.1.4 lockd: 10.1.1.3 , 10.1.1.4 rquotd: 10.1.1.3 , 10.1.1.4 mountd: 10.1.1.3 , 10.1.1.4 statd: 10.1.1.3 , 10.1.1.4
On the laptop computer add
# For NFS mount from LAN portmap: 10.1.1.2 lockd: 10.1.1.2 rquotd: 10.1.1.2 mountd: 10.1.1.2 statd: 10.1.1.2
The syntax in the above examples can be altered, e.g. 10.1.1. could be used to allow access from any machine on the 10.1.1.1/255 network
On the desktop computer add
# Allow export of root file system to LAPTOP with read/write and root access / LAPTOP(rw,no_root_squash,no_subtree_check) \ LAPTOP-W(rw,no_root_squash,no_subtree_check) /music LAPTOP(rw,no_root_squash,no_subtree_check,nohide) \ LAPTOP-W(rw,no_root_squash,no_subtree_check,nohide)
On the laptop computer add
# Allow export of root file system to DESKTOP with read/write and root access / DESKTOP(rw,no_root_squash,no_subtree_check)
- The no_root_squash option is very permissive. The root_squash option is much more secure.
- Allowing access to the entire root file system is very permissive. Restriction to a subdirectory is much more secure.
- The nohide option is required to show the contents of other mounted partitions.
Check that this file is executable on both computers
Check that this file is executable on both computers. (Not strictly necessary as /etc/rc.d/rc.nfsd will run this, but will be important if you want the computer to work as an NFS client only)
To use NFS through the firewall on your computers, follow this guide that is quoted verbatim. Thanks rworkman! From http://rlworkman.net/howtos/NFS_Firewall_HOWTO
This document is intended to give you detailed steps for making NFS bind to user-specified ports instead of random ports assigned by the portmapper. This makes it *much* easier to run a firewall on the NFS server, as you don't have to kludge something to find the NFS ports at each boot to open them with iptables. NOTE: This was written for Slackware Linux, but the general ideas should apply on pretty much any distribution. First, you'll want (it's not necessary, but handy to have for later) to make sure all of this is in /etc/services. I made sure "NFS" is in all of what I added or modified so that I can easily remove them (or just find them) if I need them later. Note that many of these are *local* additions - they are not official IANA assignments. sunrpc 111/tcp # SUN Remote Procedure Call sunrpc 111/udp # SUN Remote Procedure Call nfsd 2049/tcp # NFS server daemon nfsd 2049/udp # NFS server daemon rpc.nfs-cb 32764/tcp # RPC nfs callback rpc.nfs-cb 32764/udp # RPC nfs callback status 32765/udp # NFS status (listen) status 32765/tcp # NFS status (listen) status 32766/udp # NFS status (send) status 32766/tcp # NFS status (send) mountd 32767/udp # NFS mountd mountd 32767/tcp # NFS mountd lockd 32768/udp # NFS lock daemon/manager lockd 32768/tcp # NFS lock daemon/manager rquotad 32769/udp # NFS rquotad rquotad 32769/tcp # NFS rquotad ************************************************************************ Next, you'll need to modify your /etc/rc.d/rc.nfsd script accordingly: For other linux distributions, find the script that starts these daemons and add the needed flags. # **** Make the quota daemon listen on port 32769 if [ -x /usr/sbin/rpc.rquotad ]; then echo " /usr/sbin/rpc.rquotad -p 32769" /usr/sbin/rpc.rquotad -p 32769 fi # **** Make the mount daemon listen on port 32767 if [ -x /usr/sbin/rpc.mountd ]; then echo " /usr/sbin/rpc.mountd -p 32767" /usr/sbin/rpc.mountd -p 32767 fi Now modify the /etc/rc.d/rc.rpc script (again, for other linux distros, find the script that starts this daemon and add the needed flags). On older versions (less than 11.0) of Slackware, rpc.statd is started in rc.nfsd, so look there instead. # **** Have the portmap daemon chroot to /var/empty for increased security # **** Make the status daemon listen on port 32765 and talk on port 32766 if [ -x /sbin/rpc.portmap -a -x /sbin/rpc.statd ]; then if ! ps axc | grep -q rpc.portmap ; then echo "Starting RPC portmapper: /sbin/rpc.portmap -t /var/empty" /sbin/rpc.portmap -t /var/empty fi if ! ps axc | grep -q rpc.statd ; then echo "Starting RPC NSM (Network Status Monitor): /sbin/rpc.statd -p 32765 -o 32766" /sbin/rpc.statd -p 32765 -o 32766 fi # **** Note that you'll have to open port 32766 on the NFS clients Now make the lock daemon listen on port 32768 only and set the nfs callback port to 32764. Up to Slackware 11.0, this requires a kernel boot parameter (an append= line in lilo.conf) - a kernel stanza will look something like this: image = /boot/vmlinuz-ide-188.8.131.52 append = "lockd.udpport=32768 lockd.tcpport=32768" root = /dev/hda2 label = 184.108.40.206 read-only After 11.0, but before Slackware 13.1, this requires setting module load options in a file in the /etc/modprobe.d/ directory - I create an aptly named file of /etc/modprobe.d/nfs.conf file and add the following lines: options lockd nlm_udpport=32768 nlm_tcpport=32768 options nfs callback_tcpport=32764 # This is for NFSv4 In Slackware 13.1 and later, you will instead need to place the following in /etc/sysctl.conf: fs.nfs.nlm_udpport=32768 fs.nfs.nlm_tcpport=32768 fs.nfs.nfs_callback_tcpport=32764 Finally, you'll need to reboot the machine since the lockd module probably will refuse to unload. Once it's rebooted, you can test to make sure all of the changes "took" with "rpcinfo -p" or "pmap_dump" (rpcinfo is no longer present in Slackware 14.0 or later) -- as an example, here's a snippet of what I see here: stora # rpcinfo -p program vers proto port 100000 2 tcp 111 portmapper 100000 2 udp 111 portmapper 100024 1 udp 32766 status 100024 1 tcp 32766 status 100227 3 tcp 2049 100227 3 udp 2049 100021 3 udp 32768 nlockmgr 100021 3 tcp 32768 nlockmgr 100005 3 udp 32767 mountd 100005 3 tcp 32767 mountd Copyright 2006-2011 Robby Workman, Tuscaloosa, Alabama, USA #include <mit.h> /* Standard MIT License */ You may mirror and/or otherwise use this file as you wish so long as you retain attribution to the author. If you have any questions, comments, or suggestions for improvement, you may contact me at rworkman AT slackware.com Note: Updated 20111126 for better consistency with the Debian NFS HOWTO (since the actual port assignments aren't important, we may as well recommend the same thing in both places); thanks to David Allen for the pointers and recommendation... Note: Updated 20120820 to note pmap_dump usage instead of rpcinfo in Slackware 14+; thanks to David Allen for the heads-up on that.
Here are some example lines to allow NFS
## NFS uses TCP and UDP on ports 111, 2049, 32764-32769 # Accept TCP and UDP on port 111 from local LAN for portmap $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 111 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 111 -j ACCEPT # Accept TCP and UDP on port 2049 from local LAN for nfsd $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 2049 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 2049 -j ACCEPT # Accept TCP and UDP on port 32765 from local LAN for statd listen (set in /etc/rc.d/rc.rpc) $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 32765 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 32765 -j ACCEPT # Accept TCP and UDP on port 32766 from local LAN for statd send (set in /etc/rc.d/rc.rpc) $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 32766 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 32766 -j ACCEPT # Accept TCP and UDP on port 32767 from local LAN for mountd (set in /etc/rc.d/rc.nfsd) $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 32767 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 32767 -j ACCEPT # Accept TCP and UDP on port 32768 from local LAN for lockd (set in /etc/sysctl.conf) $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 32768 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 32768 -j ACCEPT # Accept TCP and UDP on port 32769 from local LAN for rquotad (set in /etc/rc.d/rc.nfsd) $IPTABLES -A INPUT -i $EXTIF -p tcp -s $LOCAL_LAN --dport 32769 -j ACCEPT $IPTABLES -A INPUT -i $EXTIF -p udp -s $LOCAL_LAN --dport 32769 -j ACCEPT
The work is done! Everything should now be in place. After rebooting both machines it should now be possible to:
- mount the root file system on the desktop computer on the /mnt/tmp directory on the laptop using
mount DESKTOP:/ /mnt/tmp
- mount the root file system on the laptop computer on the /mnt/tmp directory on the desktop using
mount LAPTOP:/ /mnt/tmp