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System Administration Guide: Resource Management and Network Services

NFS Troubleshooting Procedures

To determine where the NFS service has failed, you need to follow several procedures to isolate the failure. Check for the following items:

In the process of checking these items, it might become apparent that other portions of the network are not functioning, such as the name service or the physical network hardware. The System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP) contains debugging procedures for several name services. Also, during the process it might become obvious that the problem isn't at the client end. An example is if you get at least one trouble call from every subnet in your work area. In this situation, it is much more expedient to assume that the problem is the server or the network hardware near the server, and start the debugging process at the server, not at the client.

How to Check Connectivity on an NFS Client

  1. Check that the NFS server is reachable from the client. On the client, type the following command. 


    % /usr/sbin/ping bee
bee is alive

    If the command reports that the server is alive, remotely check the NFS server. See How to Check the NFS Server Remotely.

  2. If the server is not reachable from the client, ensure that the local name service is running.

    For NIS+ clients, type the following:


    % /usr/lib/nis/nisping -u
Last updates for directory eng.acme.com. :
Master server is eng-master.acme.com.
        Last update occurred at Mon Jun  5 11:16:10 1995

Replica server is eng1-replica-58.acme.com.
        Last Update seen was Mon Jun  5 11:16:10 1995

  3. If the name service is running, ensure that the client has received the correct host information by typing the following:


    % /usr/bin/getent hosts bee
129.144.83.117	bee.eng.acme.com

  4. If the host information is correct, but the server is not reachable from the client, run the ping command from another client.

    If the command run from a second client fails, see How to Verify the NFS Service on the Server.

  5. If the server is reachable from the second client, use ping to check connectivity of the first client to other systems on the local net.

    If this command fails, check the networking software configuration on the client (/etc/netmasks, /etc/nsswitch.conf, and so forth).

  6. If the software is correct, check the networking hardware.

    Try moving the client onto a second net drop.

How to Check the NFS Server Remotely

  1. Check that the NFS services have started on the NFS server by typing the following command:


    % rpcinfo -s bee|egrep 'nfs|mountd'
 100003  3,2    tcp,udp,tcp6,upd6                nfs     superuser
 100005  3,2,1  ticots,ticotsord,tcp,tcp6,ticlts,udp,upd6  mountd  superuser

    If the daemons have not been started, see How to Restart NFS Services.

  2. Check that the server's nfsd processes are responding.

    On the client, type the following command to test the UDP NFS connections from the server. 


    % /usr/bin/rpcinfo -u bee nfs
program 100003 version 2 ready and waiting
program 100003 version 3 ready and waiting

    If the server is running, it prints a list of program and version numbers. Using the -t option tests the TCP connection. If this command fails, proceed to How to Verify the NFS Service on the Server.

  3. Check that the server's mountd is responding, by typing the following command. 


    % /usr/bin/rpcinfo -u bee mountd
program 100005 version 1 ready and waiting
program 100005 version 2 ready and waiting
program 100005 version 3 ready and waiting

    If the server is running, it prints a list of program and version numbers that are associated with the UDP protocol. Using the -t option tests the TCP connection. If either attempt fails, proceed to How to Verify the NFS Service on the Server.

  4. Check the local autofs service if it is being used:


    % cd /net/wasp

    Choose a /net or /home mount point that you know should work properly. If this command fails, then as root on the client, type the following to restart the autofs service:


    # /etc/init.d/autofs stop
# /etc/init.d/autofs start

  5. Verify that file system is shared as expected on the server.


    % /usr/sbin/showmount -e bee
/usr/src										eng
/export/share/man						(everyone)

    Check the entry on the server and the local mount entry for errors. Also check the name space. In this instance, if the first client is not in the eng netgroup, that client would not be able to mount the /usr/src file system.

    Check all entries that include mounting information in all of the local files. The list includes /etc/vfstab and all the /etc/auto_* files.

How to Verify the NFS Service on the Server

  1. Become superuser or assume an equivalent role.

    For information about roles, see “Using Privileged Applications” in System Administration Guide: Security Services.

  2. Check that the server can reach the clients. 


    # ping lilac
lilac is alive

  3. If the client is not reachable from the server, ensure that the local name service is running. For NIS+ clients, type the following:


    % /usr/lib/nis/nisping -u
Last updates for directory eng.acme.com. :
Master server is eng-master.acme.com.
        Last update occurred at Mon Jun  5 11:16:10 1995

Replica server is eng1-replica-58.acme.com.
        Last Update seen was Mon Jun  5 11:16:10 1995

  4. If the name service is running, check the networking software configuration on the server (/etc/netmasks, /etc/nsswitch.conf, and so forth).

  5. Type the following command to check whether the nfsd daemon is running. 


    # rpcinfo -u localhost nfs
program 100003 version 2 ready and waiting
program 100003 version 3 ready and waiting
# ps -ef | grep nfsd
root    232      1  0  Apr 07     ?     0:01 /usr/lib/nfs/nfsd -a 16
root   3127   2462  1  09:32:57  pts/3  0:00 grep nfsd

    If the server is running, it prints a list of program and version numbers that are associated with the UDP protocol. Also use the -t option with rpcinfo to check the TCP connection. If these commands fail, restart the NFS service. See How to Restart NFS Services.

  6. Type the following command to check whether the mountd daemon is running. 


    # /usr/bin/rpcinfo -u localhost mountd
program 100005 version 1 ready and waiting
program 100005 version 2 ready and waiting
program 100005 version 3 ready and waiting
# ps -ef | grep mountd
root    145      1 0 Apr 07  ?     21:57 /usr/lib/autofs/automountd
root    234      1 0 Apr 07  ?     0:04  /usr/lib/nfs/mountd
root   3084 2462 1 09:30:20 pts/3  0:00  grep mountd

    If the server is running, it prints a list of program and version numbers that are associated with the UDP protocol. Also use the -t option with rpcinfo to check the TCP connection. If these commands fail, restart the NFS service. See How to Restart NFS Services.

  7. Type the following command to check whether the rpcbind daemon is running. 


    # /usr/bin/rpcinfo -u localhost rpcbind
program 100000 version 1 ready and waiting
program 100000 version 2 ready and waiting
program 100000 version 3 ready and waiting

    If the server is running, it prints a list of program and version numbers that are associated with the UDP protocol. If rpcbind seems to be hung, either reboot the server or follow the steps in How to Warm-Start rpcbind.

How to Restart NFS Services

  1. Become superuser or assume an equivalent role.

    For information about roles, see “Using Privileged Applications” in System Administration Guide: Security Services.

  2. To enable daemons without rebooting, type the following commands. 


# /etc/init.d/nfs.server stop
# /etc/init.d/nfs.server start

This remedy stops the daemons and restarts them, if an entry is in /etc/dfs/dfstab.

How to Warm-Start rpcbind

If the NFS server cannot be rebooted because of work in progress, you can restart rpcbind without having to restart all of the services that use RPC. Just complete a warm start as described in this procedure.

  1. Become superuser or assume an equivalent role.

    For information about roles, see “Using Privileged Applications” in System Administration Guide: Security Services.

  2. Determine the PID for rpcbind.

    Run ps to get the PID, which is the value in the second column.


    # ps -ef |grep rpcbind
    root   115     1  0   May 31 ?        0:14 /usr/sbin/rpcbind
    root 13000  6944  0 11:11:15 pts/3    0:00 grep rpcbind

  3. Send a SIGTERM signal to the rpcbind process.

    In this example, term is the signal that is to be sent and 115 is the PID for the program (see the kill(1) man page). This command causes rpcbind to create a list of the current registered services in /tmp/portmap.file and /tmp/rpcbind.file.


    # kill -s term 115
    Note –

    If you do not kill the rpcbind process with the -s term option, you cannot complete a warm start of rpcbind and must reboot the server to restore service.

  4. Restart rpcbind.

    Warm-restart the command so that the files that were created by the kill command are consulted, and the process resumes without requiring a restart of all of the RPC services. See the rpcbind(1M) man page.


    # /usr/sbin/rpcbind -w

Identifying Which Host Is Providing NFS File Service

Run the nfsstat command with the -m option to gather current NFS information. The name of the current server is printed after “currserver=”. 


% nfsstat -m
/usr/local from bee,wasp:/export/share/local
 Flags: vers=3,proto=tcp,sec=sys,hard,intr,llock,link,synlink,
		acl,rsize=32768,wsize=32678,retrans=5
 Failover: noresponse=0, failover=0, remap=0, currserver=bee

How to Verify Options Used With the mount Command

In the Solaris 2.6 release and in any versions of the mount command that were patched after the 2.6 release, no warning is issued for invalid options. The following procedure helps determine whether the options that were supplied either on the command line or through /etc/vfstab were valid.

For this example, assume that the following command has been run:


# mount -F nfs -o ro,vers=2 bee:/export/share/local /mnt

  1. Verify the options by running the following command.


    % nfsstat -m
/mnt from bee:/export/share/local
Flags:  vers=2,proto=tcp,sec=sys,hard,intr,dynamic,acl,rsize=8192,wsize=8192,
        retrans=5

    The file system from bee has been mounted with the protocol version set to 2. Unfortunately, the nfsstat command does not display information about all of the options, but using the nfsstat command is the most accurate way to verify the options.

  2. Check the entry in /etc/mnttab.

    The mount command does not allow invalid options to be added to the mount table. Therefore, verify that the options that are listed in the file match those options that are listed on the command line. In this way, you can check those options that are not reported by the nfsstat command.


    # grep bee /etc/mnttab
bee:/export/share/local /mnt nfs	ro,vers=2,dev=2b0005e 859934818