Frequently asked Questions for NFS workarounds

A network file system, or NFS, is a component of a distributed computing system that enables the sharing and assembly of remote file systems on heterogeneous networks. NFS, developed by Sun, is now a standard for document Services (rfc1904,rfc1813). Its biggest function is that it can be used to share data with different operating system computers, so it can also be considered as a file server.

The NFS network has failed and can be examined in the following ways:

(1) Check whether the NFS client and server load is too high, the network between server and client is normal;

(2) Check the correctness of the/etc/exports file;

(3) Restart NFS or Portmap services if necessary;

(4) Restart Rpcbind and NFS by running the following command:

Service Rpcbind Restart

Service NFS Start

(5) Check whether the syntax of the Mount command or/etc/fstab on the client is correct;

(6) See if the Kernel supports NFS and RPC services.


Additional: ★nfs Common troubleshooting
-------------------
1. The Rpcbind failure error
Failure phenomena:
NFS Mount:server1:: Rpc:rpcbind failure
Rpc:timed out
NFS Mount:retrying:/mntpoint
Reason:
First, there may be an incorrect IP address, hostname, or node name combination in the client's Hosts file;
Second, the server temporarily stops the service because of overloading.

2. The server not responding error
Phenomenon:
NFS server Server2 Not responding, still trying
Reason:
First, the network does not pass, with the ping command to detect.
Second, the server shuts down.

3. The NFS client fails a reboot error
Phenomenon:
After you start the client, it stops, and the following prompt message is displayed:
Setting default interface for Multicast:add net 224.0.0.0:gateway:
Client_node_name.
Reason:
FG was used in the Mount option of Etc/vfstab and the resource on the Mount server could not be successfully changed to BG or commented out until the server is available.

4. The Service not responding error
Phenomenon:
NFS Mount:dbserver:NFS:Service Not responding
NFS Mount:retrying:/mntpoint
Reason:
First, the current level is not Level 3, view with Who–r, and switch with INIT.
Second, the NFS server daemon does not exist, with Ps–ef | grep NFS Check, starting with/etc/init.d/nfs.server start.

5. The program is not registered error
Phenomenon:
NFS Mount:dbserver:RPC:Program not registered
NFS Mount:retrying:/mntpoint
Reason:
First, the current level is not Level 3.
Second, the Mountd daemon is not started and the NFS daemon is started with the/etc/init.d/nfs.server script.
Third, see if the entries in/etc/dfs/dfstab are normal.

6. The stale file handle error
Phenomenon:
Stale NFS file handle
Reason:
The shared resources on the server moved to the location, and the client uses Umount and mount to re-hook them.

7. The Unknown host error
Phenomenon:
NFS Mount:sserver1:: Rpc:unknown Host
Reason:
The contents of the Hosts file are incorrect.

8. The mount point error
Phenomenon:
MOUNT:MOUNT-POINT/DS9 does not exist.
Reason:
The mount point does not exist on the client, note the spelling of the related entry in the command line or the/etc/vfstab file.

9. The no such file error
Phenomenon:
No such file or directory.
Reason:
The mount point does not exist on the server, check the spelling of the relevant entry in the command line or the/etc/vfstab file.

10. No Route to host
Error phenomena:
[email protected] sysconfig]# Mount 10.10.11.211:/opt/b2b-data/xmldb/b2b-web1/b2b-data/xmldb-t nfs-o RW
Mount:mount to NFS server ' 10.10.11.211 ' Failed:system error:no the route to host.

Reason:
The firewall is turned on and the firewall is turned off.

11. Not owner
Phenomenon:
[Email protected]:/founder/shell]# mount-f nfs-o rw 10.10.2.3:/mnt/b2b/b2b-data/resinfo2/data/b2b-data/resinfo2
NFS Mount:mount:/data/b2b-data/resinfo2:not owner

Reason:
This is an error in the version of Solaris 10 that mounts the earlier version of NFS times.

Solve:
You need to use the-o vers=3 parameter

Example:
[Email protected]:/founder/shell]# mount-f nfs-o vers=3 10.10.2.3:/mnt/b2b/b2b-data/resinfo2/data/b2b-data/ Resinfo2

12, Rpc:program not registered & retrying
Phenomenon:
NFS mount:10.10.2.3:: Rpc:program not registered
NFS Mount:retrying:/data/b2b-data/resinfo2

Reason:
The NFS shared-side service is not started.

WORKAROUND: You need to restart the NFS service on the share side,
Linux:
Mount:RPC:Program not registered
#service NFS Restart

Solaris:
Mount:RPC:Program not registered
#/etc/rc.d/init.d/nfs restart

13. Can ' t contact Portmapper:RPC:Remote system Error-connection refused
Phenomenon:
#exportfs-A
Can ' t contact Portmapper:RPC:Remote system Error-connection refused

Reason:
This error message occurs because the Portmap on the sever side is not started.

Solve:
#service Portmap Start
#service PCMCIA Start

----------------------------------------------------------------------------

NFS Failure Resolution:
1, NFSD did not start up
The first step is to confirm that the NFS output list is present, otherwise NFSD will not start. The EXPORTFS command can be used to check if the EXPORTFS command has no results returned or is not returned correctly, you need to check the/etc/exports file.
2, MOUNTD process does not start
The MOUNTD process is a remote procedure call (RPC) that responds to requests from the client to install the (Mount) file system. The MOUNTD process finds out which file systems can be used by remote clients by locating the/etc/xtab file. In addition, through the MOUNTD process, users can know what file systems are currently being assembled by remote file systems and learn the list of remote clients. See if Mountd is up and running can be viewed using command rpcinfo, which normally should look like this in the list of outputs:
100005 1 UDP 1039 Mountd
100005 1 TCP 1113 Mountd
100005 2 UDP 1039 Mountd
100005 2 TCP 1113 Mountd
100005 3 UDP 1039 Mountd
100005 3 TCP 1113 Mountd
If you don't get up, you can check if the Portmap component is installed.
Rpm-qa|grep Portmap
3. FS type NFS no supported by kernel
Kernel does not support NFS file system, recompile kernel can be resolved.
4. Cant contact portmapper:RPC:Remote system error-connection refused
This error message occurs because the Portmap on the sever side is not started.
5. Mount Clntudp_create:RPC:Program not registered
NFS does not start up, you can use the SHOWMOUT-E Host command to check if NFS server is up and running properly.
6, Mount:localhost:/home/test failed, reason given by Server:permission denied
This hint is a hint that may occur when the client wants to mount NFS server, meaning that the native does not have permission to mount the directory on NFS server. The workaround is, of course, to modify the NFS server.
7, blocked by the firewall
For this reason, many people neglect that in the strict network environment, we usually shut down all the ports on Linux, when we need to use which port to open. For NFS, the default is to use port 111, so we'll first check if this port is open, and the Tcp_wrappers setting.

Reference: http://blog.csdn.net/lincy100/article/details/6417743

Http://www.361way.com/nfs-mount-nobody/2616.html

Http://www.haiyun.me/archives/centos-nfs-port.html

Fixed NFS boot port for easy iptables Setup
Http://www.haiyun.me/archives/centos-nfs-port.html
NFS mount and write failures
Http://www.cnblogs.com/linuxzkq/p/NFS.html
NFS can only be mounted as a workaround for nobody
Http://www.361way.com/nfs-mount-nobody/2616.html
NFS Case Record---Write permission resolution process in production
Http://blog.sina.com.cn/s/blog_506ed9e6010113z2.html

This article is from the "Boyhack" blog, make sure to keep this source http://461205160.blog.51cto.com/274918/1736527

Frequently asked Questions for NFS workarounds