NFSv4 is a tried and tested method of allowing client servers to access files over a network, in a very similar fashion to how the files would be accessed on a local file system. As a very mature piece of software, it has been successfully developed and used on production environments for over 15 years, and it is still widely accepted and supported with a long life ahead of it.
Setting it up is pretty easy and straight forward. As this is a network file system, it is strongly recommended to setup a private switch or private network between to the servers to ensure the lowest latency, as well as better security.
NFS Server – Installation
Install the required packages on the NFS server:
# Ubuntu and Debian [root@nfs01 ~]# apt-get update [root@nfs01 ~]# apt-get install rpcbind nfs-common nfs4-acl-tools nfs-kernel-server
NFS Server – Configuration
Out of the box, NFSv4 has the following option set which is getting outdated sorely at this time:
– Sets random ephemeral ports upon daemon startup.
– Enables only 8 NFS threads
To make things more easier for admin’s to lock down the firewalls, we are going to set static ports, and also enable 64 NFS threads since you will most likely run into IO problems before you hit this limit as it was meant for much older systems.
Stop the services so we can unload the lockd kernel module and configure the services. This step cannot be skipped!
# Ubuntu 12.04 and Ubuntu 14.04 [root@nfs01 ~]# service nfs-kernel-server stop [root@nfs01 ~]# service statd stop [root@nfs01 ~]# service idmapd stop [root@nfs01 ~]# service rpcbind stop [root@nfs01 ~]# modprobe -r nfsd nfs lockd # Debian 7 [root@nfs01 ~]# service nfs-kernel-server stop [root@nfs01 ~]# service nfs-common stop [root@nfs01 ~]# service rpcbind stop [root@nfs01 ~]# modprobe -r nfsd nfs lockd
Update the NFS thread count by:
[root@nfs01 ~]# vim /etc/default/nfs-kernel-server ... RPCNFSDCOUNT=64 RPCNFSDPRIORITY=0 RPCMOUNTDOPTS="--manage-gids" NEED_SVCGSSD="no" RPCSVCGSSDOPTS="" ...
Next, set the domain as all servers and clients should resides within the same domain:
[root@nfs01 ~]# vim /etc/idmapd.conf [General] Domain = yourdomain.com
Update nfs-common to disable statd and rpc.gssd, then require idmapd:
# Ubuntu 12.04 and Ubuntu 14.04 [root@nfs01 ~]# vim /etc/default/nfs-common NEED_STATD=no STATDOPTS= NEED_GSSD=no # Debian 7 [root@nfs01 ~]# vim /etc/default/nfs-common NEED_STATD=no STATDOPTS= NEED_IDMAPD=yes NEED_GSSD=no
Open the firewall to allow your private network access to the NFS services. You may have to adjust your rules as my private network resides on eth2. Do not allow this on the public interface without adjusting the source IP’s accordingly!
[root@nfs01 ~]# ufw allow in on eth2 to 192.168.1.0/24 proto tcp [root@nfs01 ~]# ufw allow in on eth2 to 192.168.1.0/24 proto udp
NFSv4 uses a pseudo filesystem for the exports. A pseudo filesystem allows NFS clients to browse the hierarchy of exported file systems, but remains limited to paths that are actually exported. There are a number of ways to go about this, but for this guide, we’ll assume the pseudo filesystem root will be /exports, and we’ll simply bind mount the desired directories into the /exports folder.
For this example, I am looking to export in /data. So we’ll bind mount that to the /exports folder as follows:
[root@nfs01 ~]# mkdir /data [root@nfs01 ~]# touch /data/test-file [root@nfs01 ~]# mkdir /exports [root@nfs01 ~]# mkdir /exports/data [root@nfs01 ~]# echo "/data /exports/data none bind 0 0" >> /etc/fstab [root@nfs01 ~]# mount -a [root@nfs01 ~]# ls -al /exports/data total 8 drwxr-xr-x 2 root root 4096 Jan 11 22:19 . drwxr-xr-x 3 root root 4096 Jan 11 22:03 .. -rw-r--r-- 1 root root 0 Jan 11 22:03 test-file
If you can see the file, test-file, within /exports/data, then everything is setup properly.
Export the directory to be shared, along with its permissions, in /etc/exports:
[root@nfs01 ~]# vim /etc/exports /exports 192.168.1.0/24(ro,no_subtree_check,fsid=0,crossmnt) /exports/data 192.168.1.0/24(rw,no_subtree_check,no_root_squash)
Now start the services, and ensure they will start at boot time:
# Ubuntu 12.04 and Ubuntu 14.04 [root@nfs01 ~]# service rpcbind start [root@nfs01 ~]# service idmapd start [root@nfs01 ~]# service nfs-kernel-server start; update-rc.d nfs-kernel-server enable # Debian 7 [root@nfs01 ~]# service rpcbind start; insserv rpcbind [root@nfs01 ~]# service nfs-common start; insserv nfs-common [root@nfs01 ~]# service nfs-kernel-server start; insserv nfs-kernel-server
Check to make sure the services are running:
[root@nfs01 ~]# showmount -e
Export list for nfs01:
/exports/data 192.168.1.0/24
/exports 192.168.1.0/24
[root@nfs01 ~]# rpcinfo -p
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100003 2 tcp 2049 nfs
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 2 tcp 2049
100227 3 tcp 2049
100003 2 udp 2049 nfs
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs
100227 2 udp 2049
100227 3 udp 2049
100021 1 udp 39482 nlockmgr
100021 3 udp 39482 nlockmgr
100021 4 udp 39482 nlockmgr
100021 1 tcp 60237 nlockmgr
100021 3 tcp 60237 nlockmgr
100021 4 tcp 60237 nlockmgr
100005 1 udp 39160 mountd
100005 1 tcp 34995 mountd
100005 2 udp 34816 mountd
100005 2 tcp 56338 mountd
100005 3 udp 49147 mountd
100005 3 tcp 51938 mountd
NFS Client – Installation
Now that the NFS server is ready, the NFS clients now need to be setup to connect. Install the required packages on the NFS clients by:
# Ubuntu or Debian [root@web01 ~]# apt-get update [root@web01 ~]# apt-get install rpcbind nfs-common nfs4-acl-tools
NFS Client – Configuration
Stop the services so we can unload the lockd kernel module and configure the services. This step cannot be skipped!
# Ubuntu 12.04 and Ubuntu 14.04 [root@web01 ~]# service nfs-kernel-server stop [root@web01 ~]# service statd stop [root@web01 ~]# service idmapd stop [root@web01 ~]# service rpcbind stop [root@web01 ~]# modprobe -r nfsd nfs lockd # Debian 7 [root@web01 ~]# service nfs-kernel-server stop [root@web01 ~]# service nfs-common stop [root@web01 ~]# service rpcbind stop [root@web01 ~]# modprobe -r nfsd nfs lockd
Next, set the domain as all servers and clients should resides within the same domain:
[root@web01 ~]# vim /etc/idmapd.conf [General] Domain = yourdomain.com
Update nfs-common to disable statd and rpc.gssd, then require idmapd:
# Ubuntu 12.04 and Ubuntu 14.04 [root@web01 ~]# vim /etc/default/nfs-common NEED_STATD=no STATDOPTS= NEED_GSSD=no # Debian 7 [root@web01 ~]# vim /etc/default/nfs-common NEED_STATD=no STATDOPTS= NEED_IDMAPD=yes NEED_GSSD=no
Now start the services, and ensure they will start at boot time:
# Ubuntu 12.04 and Ubuntu 14.04 [root@web01 ~]# service rpcbind start [root@web01 ~]# service idmapd start # Debian 7 [root@web01 ~]# service rpcbind start; insserv rpcbind [root@web01 ~]# service nfs-common start; insserv nfs-common
Confirm the NFS clients can see the NFS server:
[root@web01 ~]# showmount -e 192.168.1.1
Export list for 192.168.1.1:
/var/www/vhosts 192.168.1.0/24
[root@web01 ~]# rpcinfo -p 192.168.1.1
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100024 1 udp 662 status
100024 1 tcp 662 status
100003 2 tcp 2049 nfs
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 2 tcp 2049
100227 3 tcp 2049
100003 2 udp 2049 nfs
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs
100227 2 udp 2049
100227 3 udp 2049
100021 1 udp 32769 nlockmgr
100021 3 udp 32769 nlockmgr
100021 4 udp 32769 nlockmgr
100021 1 tcp 32803 nlockmgr
100021 3 tcp 32803 nlockmgr
100021 4 tcp 32803 nlockmgr
100005 1 udp 892 mountd
100005 1 tcp 892 mountd
100005 2 udp 892 mountd
100005 2 tcp 892 mountd
100005 3 udp 892 mountd
100005 3 tcp 892 mountd
Configure the mount point in /etc/fstab:
[root@web01 ~]# vim /etc/fstab 192.168.1.1:/data /data nfs4 sec=sys,noatime 0 0
Now create the placeholder directory on the client, mount, and verify it works:
[root@web01 ~]# mkdir /data [root@web01 ~]# mount -a [root@web01 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/xvda1 20G 1.2G 18G 7% / none 4.0K 0 4.0K 0% /sys/fs/cgroup udev 484M 8.0K 484M 1% /dev tmpfs 99M 404K 99M 1% /run none 5.0M 0 5.0M 0% /run/lock none 495M 0 495M 0% /run/shm none 100M 0 100M 0% /run/user 192.168.13.1:/data 20G 1.2G 18G 7% /data [root@web01 ~]# [root@web01 ~]# grep /data /proc/mounts 192.168.1.1:/data /data nfs rw,noatime,vers=3,rsize=32768,wsize=32768,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.1.1,mountvers=3,mountport=892,mountproto=tcp,local_lock=none,addr=192.168.1.1 0 0 [root@web01 ~]# [root@web01 ~]# touch /data/test-file [root@web01 ~]# ls -al /data/test-file -rw-r--r-- 1 root root 0 Dec 20 01:45 /data/test-file
Finally, confirm the user mapping is the same on both servers. You can test to ensure both the server and the client’s show the same UID’s by:
# Create a user on the NFS server: [root@nfs01 ~]# useradd -u 6000 testuser # Create the same user on the NFS client: [root@web01 ~]# useradd -u 6000 testuser # Set the ownership of a test file on the NFS server: [root@nfs01 ~]# touch /data/test-file01 [root@nfs01 ~]# chown testuser:testuser /data/test-file01 # Check the ownership of the test file on the NFS server: [root@nfs01 ~]# ls -al /data/test-file01 # Confirm the client sees the same ownership: [root@web01 ~]# ls -al /data/test-file01