NFSv4, network file system version 4, is the new version of NFS (for setting up the older NFSv3, see Nfs) with new features like strong authentication and integrity via Kerberos and SPKM-3, improved performance, safe file caching, lock migration, UTF-8, ACLs and better support for Windows file sharing semantics.
This article covers installing and configuring NFSv4.
- 1 Installing
- 2 Configuring
- 3 Troubleshooting
# pacman -S nfs-utils
The server configuration is very thorough.
First we'll need to edit our exports in Template:Filename. A typical NFSv4 export would look like this:
/export 192.168.0.12(rw,fsid=0,no_subtree_check,async,no_root_squash) /export/music 192.168.0.12(rw,no_subtree_check,async,no_root_squash)
/export is the NFS root here (due to the Template:Codeline entry). Everything else that you want to be shared over NFS must be accessible under /export.
For exporting directories outside the NFS root, see below.
Exporting directories outside your NFS root
To do this, you'll need to use bind mounts. For example, to bind /home/john to /export/john:
# mount --bind /home/john /export/john
Then, /export/john needs to be added to Template:Filename:
/export 192.168.0.12(rw,fsid=0,no_subtree_check,async,no_root_squash) /export/music 192.168.0.12(rw,no_subtree_check,async,no_root_squash) /export/john 192.168.0.12(rw,no_subtree_check,async,no_root_squash,nohide)
/home/john /export/john none bind 0 0
Then, Template:Filename needs to be edited. You'll need to at the very least specify your Domain there. Example:
[General] Verbosity = 1 Pipefs-Directory = /var/lib/nfs/rpc_pipefs Domain = archlinux.org [Mapping] Nobody-User = nobody Nobody-Group = nobody
To allow network access to the nfs server you should edit /etc/hosts.allow. The following example opens these services to anyone:
nfsd: ALL rpcbind: ALL mountd:ALL
This is a very insecure way of allowing host access. To get better control over who is allowed to access the daemons, hosts.deny should be everyone, and hosts.allow should specifically allow certain people. In this example, 192.168.0.101 should be the IP address of the person(s) allowed to access it. The numbers after the '/' is the netmask:
nfsd: 192.168.0.101/255.255.255.255 rpcbind: 192.168.0.101/255.255.255.255 mountd: 192.168.0.101/255.255.255.255
This examples enables access for anyone on that network:
nfsd: 192.168.0.0/255.255.255.0 rpcbind: 192.168.0.0/255.255.255.0 mountd: 192.168.0.0/255.255.255.0
For finer control, read the hosts_access(5) man page.
Starting the server
To start the NFS server, just do:
# /etc/rc.d/rpcbind start # /etc/rc.d/nfs-common start # /etc/rc.d/nfs-server start
If you want to tweak the configuration, feel free to edit Template:Filename to fit your needs.
The client configuration is more simple.
Client ID mapping
Template:Filename needs to be edited on all clients and the Domain entry should be identical to the one on the server. Example:
[General] Verbosity = 1 Pipefs-Directory = /var/lib/nfs/rpc_pipefs Domain = archlinux.org [Mapping] Nobody-User = nobody Nobody-Group = nobody [Translation] Method = nsswitch
You will need to allow rpcbind for the server's ip:
Mounting the partitions on the client
On the client, to mount the NFSv4 partition: Make sure that nfs module is loaded. (lsmod | grep nfs). If not execute the next command "modprobe nfs"
# /etc/rc.d/rpcbind start # /etc/rc.d/nfs-common start # mount -t nfs4 server:/ /mnt/server/ # mount -t nfs4 server:/music /mnt/music/ # mount -t nfs4 server:/john /mnt/john
Replacing 'server' with the hostname or IP address of your NFS server and of course 'server', 'music' and 'john' with the names of whatever directories you exported on the server.
If you want the NFS volumes to mount automatically on bootup, add them to Template:Filename. For example:
server:/ /mnt/server nfs4 async,user 0 0
Remember to add netfs in the daemons array at /etc/rc.conf in order to mount nfs volumes at boot.
Client & Server: Time Synchronization
In order for NFS to function properly, both server and client must have closely matching time values. If the clocks on the clients differ from the server too much, then basic functions like file copy operations may hang for a very long time leaving the system unusable until they resume. The clocks do not have to match to micro/nano second accuracies, but ideally they should be within 1 second of each other.
The NTP system is recommended to sync both the server and the clients to the highly accurate NTP servers available on the Internet. For a small system like a home network, the ntpdate utility may be used to sync both servers and clients to the same time. For a larger installation, it may be desirable to install an OpenNTP server (see NTP) onto the same machine acting as the NFS server, and then all clients on the network would sync time values from the server. This has the advantage of lowering the stress on the external NTP servers, and in assuring that the NFS clients will use the exact time that the NFS server has, even if the NFS server experiences some drift.
Common problems and how to overcome them
messages.log contains "nfsdopenone: Opening /proc/net/rpc/nfs4.nametoid/channel failed: errno 2 (No such file or directory)"
Add 'nfsd' to /etc/rc.conf modules array (NOTE: you may need to add "Verbosity = 3" to /etc/idmapd.conf and restart the services above to receive the error)
exportfs: /etc/exports:2: syntax error: bad option list
Delete all space from the option list in /etc/exports
mount.nfs4: No such device
Check that you have loaded nfs module
lsmod | grep nfs
and if previous returns empty or only nfsd-stuff, do
mount.nfs4: access denied by server while mounting
Check that the permissions on your client's folder are correct ('755' worked for me --Zenlord 12:01, 7 May 2010 (EDT))
If you find that you can't set the permissions on files properly,
make sure the user/group you're chowning are on both the client and server.
If that doesn't help, try modifying these lines in
# /etc/conf.d/nfs-common.conf # Do you want to start the statd daemon? It is not needed for NFSv4. NEED_STATD="no" # Do you want to start the idmapd daemon? It is only needed for NFSv4. NEED_IMAPD="yes"
Restart the nfs-common daemon for the changes to take effect. I restarted all the other daemons as well, just to be sure.