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This page describes how to mount use '''NFS partition client''' inside VEa container.

== NFS server ==Currently OpenVZ kernel doesn't include kernel NFS server support. Howether you are still able to use user space {{Note|see [[NFS server inside VEcontainer]]for info about nfsd.

== NFS client ==Mounting filesystems from the '''hardware node''' can be performed more elegantly using [[Bind mounts]].}} === Preparations ======= Software =Prerequisites ===

# vzctl version 3.0.13 or higher (do <code>vzctl --version</code>)# kernel version 2.6.18-028test006 or higher (2.6.18-028stab* will do), or any recent RHEL5-based or 2.6.20-based kernel. Note: In all the kernels earlier than 028stab038, kernel NFS support can be given to a container by setting:  sunrpc.ve_allow_rpc =1 fs.nfs.ve_allow_nfs = 1 kernel.ve_allow_kthreads = 1 This can be done by adding the above lines into /etc/sysctl.conf on the hardware node, and then running <code>sysctl -p</code>. === Prepare the VE HN === For NFS mounts to work in the containers with the RHEL5-based kernels you must enable kernel threads in the container by setting <code>kernel.ve_allow_kthreads=1</code> in <code>/etc/sysctl.conf</code>. RHEL7-based kernels support [https://www.centos.org/docs/5/html/Deployment_Guide-en-US/ch-nfs.html three different NFS protocol versions]:{{Quote|NFS version 2 (NFSv2) is older and is widely supported.NFS version 3 (NFSv3) has more features, including 64bit file handles, Safe Async writes and more robust error handling.NFS version 4 (NFSv4) works through firewalls and on the Internet, no longer requires portmapper, supports ACLs, and utilizes stateful operations.Red Hat Enterprise Linux supports NFSv2, NFSv3, and NFSv4 clients, and when mounting a file system via NFS, Red Hat Enterprise Linux uses NFSv3 by default, if the server supports it.}} Accordingly, there are three kernel modules: <code>nfs</code> (for NFSv2), <code>nfsv3</code>, and <code>nfsv4</code>. As [[NFS server inside container]] currently only supports NFSv3, it's very likely that you'll need to load <code>nfsv3</code> module for clients.  # modprobe nfs You will probably want the nfs module to load automatically on reboots. One way to do this is to put the modprobe command in your /etc/rc.d/rc.local file:  modprobe nfs Alternatively, you can add a new line with <code>nfs</code> to your /etc/modules or /etc/modules.conf file. ===Prepare the container ===To allow VE a container to use NFS filesystem , you will need to start it fith with "nfs" feature enabled.If the container is running while you set the <code>--features nfs:on<pre/code>, you will need to reboot it.  # vzctl set 100 101 --features "nfs:on" --save # vzctl start 101</pre>

=== Mounting NFS ===Make sure that packages <code>nfs-utils</code> and <code>nfs-utils-lib</code> or similar are installed in a container. Also make sure that the <code>portmap</code> (or <code>rpcbind</code>) service is started, otherwise the mount with default options will fail and require the <code>-nolock</code> option. See the [[NFS#Known issues|known issues]] for more information. Assuming that you already have NFS server set up at <code>192.168.0.1:/nfs_pub</code> , mounting will be simple

For more details on how to setup NFS mount , see [http://nfs.sourceforge.net/nfs-howto/ar01s04.htm html NFS-client HOWTO] == Known issues ==* There are quite a few parameters in NFS, so sometimes it doesn't work due to misconfiguration. We've created a separate page describing such situations: [[NFS doesn't work]].* Package nfs-common can not be installed. Make sure you start <code>portmap</code> before trying to install nfs-common.** For Ubuntu/Debian OpenVZ containers, the <code>portmap/rpcbind</code> service may not start automatically. However, you can enable it by editing the <code>/etc/default/nfs-common</code> configuration file. == See also ==* [http://nfs.sourceforge.net/nfs-howto/ar01s04.html NFS-client HOWTO]