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| | There are two ways to setup NFS server on common [[HN]]: | | There are two ways to setup NFS server on common [[HN]]: |
| | use a user-space NFS server daemon or use an in-kernel implementation | | use a user-space NFS server daemon or use an in-kernel implementation |
| − | of NFS server. | + | of NFS server. Some peculiarities appear if you intend to run NFS server |
| − | | + | in [[VE]]. |
| − | {{Note|for information about NFS client inside container, see [[NFS]].}}
| |
| | | | |
| | == Kernel NFS server == | | == Kernel NFS server == |
| − | | + | Binary RPMs that are provided by OpenVZ community contain kernels compiled |
| − | Kernel-space NFS server is supported by latest RHEL5 and RHEL6 based kernels and since vzctl-3.0.24.
| + | without NFS server support. Thus you have to |
| − | | + | [[Kernel build|recompile the kernel]] with <code>CONFIG_NFSD=m</code>. After booting in this kernel you'll be able |
| − | NB! Currently only NFSv3 is supported - no NFSv4 support yet.
| + | to use NFS server on [[HN]]. |
| − | | + | In-kernel NFS server runs kernel threads to service requests of clients. |
| − | === Prerequisites ===
| + | But for security reasons kernel threads are prohibited in [[VE]]s! So you won't |
| − | In order to run an NFS server inside a container, make sure:
| + | be able to run NFS server inside [[VE]] without patching the kernel. |
| − | * '''nfsd kernel module is loaded on host system before starting a container'''
| |
| − | * '''nfsd feature for a container is turned on''' (<code>vzctl set $CTID --feature nfsd:on --save</code>)
| |
| − | | |
| − | === Setup ===
| |
| − | * Make sure that rpcbind service is started before nfs service:
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| − | : <code>chkconfig rpcbind on && service rpcbind start</code>
| |
| − | * Disable NFSv4 and nfsd module loading warnings in /etc/sysconfig/nfs by uncommenting the following lines:
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| − | MOUNTD_NFS_V3="yes"
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| − | RPCNFSDARGS="-N 4"
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| − | NFSD_MODULE="noload"
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| − | * Start NFS service:
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| − | : <code>chkconfig nfs on && service nfs start</code>
| |
| − | | |
| − | === Troubleshooting ===
| |
| − | | |
| − | Make sure that:
| |
| − | # you have enabled nfsd feature for your container
| |
| − | # nfsd kernel module is loaded before you started the container
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| − | | |
| − | ==== rpcbind ====
| |
| − | | |
| − | If you see this:
| |
| − | <pre>
| |
| − | # service nfs start
| |
| − | ...
| |
| − | Starting NFS services: [ OK ]
| |
| − | Starting NFS quotas: Cannot register service: RPC: Unable to receive; errno = Connection refused
| |
| − | rpc.rquotad: unable to register (RQUOTAPROG, RQUOTAVERS, udp).
| |
| − | </pre>
| |
| − | | |
| − | It means you haven't started rpcbind service. Solution:
| |
| − | <pre>chkconfig rpcbind on && service rpcbind start</pre>
| |
| − | | |
| − | ==== nfsd module ====
| |
| − | If you see this:
| |
| − | <pre>
| |
| − | # service nfs start
| |
| − | ....
| |
| − | Starting NFS daemon: rpc.nfsd: Unable to access /proc/fs/nfsd errno 2 (No such file or directory).
| |
| − | Please try, as root, 'mount -t nfsd nfsd /proc/fs/nfsd' and then restart rpc.nfsd to correct the problem
| |
| − | [FAILED]
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| − | # mount -t nfsd nfsd /proc/fs/nfsd
| |
| − | mount: unknown filesystem type 'nfsd'
| |
| − | </pre>
| |
| − | | |
| − | It means you haven't loaded nfsd kernel module on host before starting container.
| |
| − | | |
| − | ==== warnings ====
| |
| − | | |
| − | If you see this:
| |
| − | <pre>
| |
| − | # /etc/init.d/nfs start
| |
| − | FATAL: Module nfsd not found.
| |
| − | FATAL: Error running install command for nfsd
| |
| − | ...
| |
| − | </pre>
| |
| − | | |
| − | It is actually harmless, you don't need to do anything. In case you want this to go away, uncomment (or add) the line
| |
| − | | |
| − | NFSD_MODULE="noload"
| |
| − | | |
| − | in <code>/etc/sysconfig/nfs</code> file.
| |
| | | | |
| | == User-space NFS server == | | == User-space NFS server == |
| − | Advantage of user-space NFS server is that it does not require kernel support. | + | Advantage of user-space NFS server is that it can be ran without any support in the kernel. |
| − | Also if it crashes — there is no crash of the system: just one process dies, not the kernel! | + | Also if it crashes — there is no crash of a system: just one process crashes, not kernel! |
| − | The disadvantage of user-space NFS server is its productivity: no one can be faster than in-kernel implementation. | + | The disadvantage of user-space NFS server is its productivity: no one can be faster then in-kernel implementation. |
| | | | |
| | One well-known implementation of NFS server is "The LINUX User-Space NFS Server" by Olaf Kirch. | | One well-known implementation of NFS server is "The LINUX User-Space NFS Server" by Olaf Kirch. |
| | Some Linux distributions contain this package: Debian Sarge (<code>nfs-user-server</code>), OpenSUSE 10.0 (<code>nfs-server</code>). | | Some Linux distributions contain this package: Debian Sarge (<code>nfs-user-server</code>), OpenSUSE 10.0 (<code>nfs-server</code>). |
| | For other distributions you can download sources (for example from Debian repository) and compile it. | | For other distributions you can download sources (for example from Debian repository) and compile it. |
| − | There is a small trick you have to know about running <code>mountd</code> and <code>nfsd</code> (these two daemons and <code>portmap</code> constitute a user-space server). You should run them with the <code>-r</code> option: | + | There is a small trick you have to know about runing <code>mountd</code> and <code>nfsd</code> (these two daemons and <code>portmap</code> constitute a user-space server). You should run them with <code>-r</code> option: |
| | <pre> | | <pre> |
| | # portmap | | # portmap |
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| | # rpc.nfsd -r | | # rpc.nfsd -r |
| | </pre> | | </pre> |
| − | The reason is that these daemons check the major number of the device where the directory to export resides. | + | The reason is that these daemons check major number of device where the directory to export resides. |
| − | If major equals 0 then daemons assume that it is NFS and don't want to re-export it. Symptoms are | + | If major equals 0 then daemons suppose that it is NFS and don't want to re-export it. Symptoms are |
| − | that clients will always get a "permission denied" error. Simfs (the file system on which container is located) | + | that clients will always get a "permission denied" error. Simfs (the file system on what VE is located) |
| − | is associated with so called unnamed device, in which major equals 0. So, to prevent daemons from checking for | + | is assosiated with so called unnamed device, which major equals 0. So, to prevent daemons from checking for |
| | re-exporting — just use this <code>-r</code> option. | | re-exporting — just use this <code>-r</code> option. |
| | | | |
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| | implementation: [http://unfs3.sourceforge.net/ unfs3]. It implements v3 of NFS protocol standard. | | implementation: [http://unfs3.sourceforge.net/ unfs3]. It implements v3 of NFS protocol standard. |
| | | | |
| − | Please note that the user-space NFS server does not provide locking, or at least I couldn't get locking to work - [[User:Elronxenu|Elronxenu]] 19:49, 15 November 2007 (EST)
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| − |
| |
| − | === On Debian Lenny ===
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| − |
| |
| − | The current stable debian version 5.0 (lenny) provides two packages for user space nfs support: <code>nfs-user-server</code> and <code>unfs3</code>. Here i describe my experiences with them --[[User:Strimo|Strimo]] 17:47, 16 February 2009 (UTC)
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| − |
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| − | It seems that also the unfs3 package has been removed from the debian repositories. --[[Special:Contributions/95.21.175.189|95.21.175.189]] 23:39, 30 July 2011 (UTC)
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| − |
| |
| − | ==== nfs-user-server ====
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| − |
| |
| − | IMPORTANT : read http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=515957 , nfs-user-server was removed
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| − |
| |
| − | <pre>
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| − | aptitude install nfs-user-server
| |
| − | </pre>
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| − |
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| − | First i used nfs-user-server package since i didn't know unfs3. After installing i always got the '''permission denied''' error when i tried to mount any exported path until i found this article. So i patched the /etc/init.d/nfs-user-server file to include the <code>-r</code> parameter by adding <code>-- -r</code> to the <code>start-stop-daemon</code> line responsible for starting <code>rpc.mountd</code> and <code>rpc.nfsd</code>:
| |
| − |
| |
| − | <pre>
| |
| − | start-stop-daemon --start --oknodo --quiet --exec /usr/sbin/rpc.nfsd -- -r
| |
| − | start-stop-daemon --start --oknodo --quiet --exec /usr/sbin/rpc.mountd -- -r
| |
| − | </pre>
| |
| − |
| |
| − | After the modification and a nfs server restart (<code>/etc/init.d/nfs-user-server restart</code>) i was able to mount a nfs share. At first the nfs server seems to work fine but anytime i want to edit any text file (using nano or mcedit) i got strange errors on writing to the file and i never solved the problem nor detected why this happens. So i switched to unfs3 ...
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| − |
| |
| − | <b>Note</b>: nfsmount from busybox not works with nfs-user-server in Debian Lenny, it write message "rpc failed: 2" when I try boot from nfs server. unfs3 works fine.
| |
| − | Such problem into Ubuntu: https://bugs.launchpad.net/ubuntu/+source/nfs-user-server/+bug/189593
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| − |
| |
| − | ==== unfs3 ====
| |
| − |
| |
| − | <pre>
| |
| − | aptitude install unfs3
| |
| − | </pre>
| |
| − |
| |
| − | Works fine until now. Note that both unfs3 and nfs-user-server do not support file locking!
| |
| − | NOTE: I tested on centos 5.6 using unfs3 and I had to run the /etc/init.d/nfs service and see it work before I could use unfs. also use exports -a before using sudo /usr/sbin/unfsd -T -e /etc/exports
| |
| − |
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| − | === On CentOS 5 ===
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| − |
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| − | If you are running RedHat/CentOS, you can [http://dag.wieers.com/rpm/packages/unfs3/ get unfs3 from the DAG repository]
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| − |
| |
| − | == External links ==
| |
| − | * [http://nfs.sourceforge.net/ Linux NFS Overview, FAQ and HOWTO Documents]
| |
| − | * [http://www.tldp.org/LDP/nag/nag.html The Network Administrators' Guide by Olaf Kirch]
| |
| − | * [http://unfs3.sourceforge.net/ unfs3 homepage]
| |
| − | * [http://packages.qa.debian.org/n/nfs-user-server.html Overview of nfs-user-server source package]
| |
| | | | |
| | [[Category: HOWTO]] | | [[Category: HOWTO]] |
| | [[Category: Networking]] | | [[Category: Networking]] |
