General troubleshooting recommendations

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(Adding some troubleshooting steps from Trond's email)
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Depending on your configuration, there's a number of ways that NFS can fail to work.  Sometimes it can be difficult to determine exactly why it is not working.  This page describes some general techniques for diagnosing the issue.
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If you cannot resolve your problem and plan to report it to the developer, see [[Reporting bugs]].
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==I need to get detailed debug output of the client/server interactions==
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== Check server's exports ==
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Start `tcpdump -s 9000 -w /tmp/dump.out port 2049` on the client, then conduct the client/server interaction.
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An easy first thing to doublecheck is that your server is exporting what you think it is. On the server, run the command:
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==I need to "reboot" the NFSv4 server but don't want to shut down the machine==
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exportfs -v
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If you need to make modifications, edit /etc/exports and re-export using the command
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exportfs -r
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Remember that pseudo-filesystems in NFSv4 work very differently than NFSv3.  Review the <a href="http://www.citi.umich.edu/projects/nfsv4/linux/using-nfsv4.html">Using NFSv4</a> directions if you have questions.
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== Check server mount functionality ==
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Try mounting the nfs4 export on the server itself by mounting localhost:/.  This will isolate whether the problem is with the server configuration.
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==Getting detailed debug output of the client/server interactions==
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Start `tcpdump -s 9000 -w /tmp/dump.out port 2049` on the client, then conduct the client/server interaction.  Review the /tmp/dump.out file (or include it with your bug report).
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=="Reboot" the NFSv4 server without shutting down the machine==
Just shut down rpc.nfsd and start it again.
Just shut down rpc.nfsd and start it again.

Revision as of 20:45, 28 June 2005

Depending on your configuration, there's a number of ways that NFS can fail to work. Sometimes it can be difficult to determine exactly why it is not working. This page describes some general techniques for diagnosing the issue.

If you cannot resolve your problem and plan to report it to the developer, see Reporting bugs.

Contents

Check server's exports

An easy first thing to doublecheck is that your server is exporting what you think it is. On the server, run the command:

exportfs -v

If you need to make modifications, edit /etc/exports and re-export using the command

exportfs -r

Remember that pseudo-filesystems in NFSv4 work very differently than NFSv3. Review the <a href="http://www.citi.umich.edu/projects/nfsv4/linux/using-nfsv4.html">Using NFSv4</a> directions if you have questions.

Check server mount functionality

Try mounting the nfs4 export on the server itself by mounting localhost:/. This will isolate whether the problem is with the server configuration.

Getting detailed debug output of the client/server interactions

Start `tcpdump -s 9000 -w /tmp/dump.out port 2049` on the client, then conduct the client/server interaction. Review the /tmp/dump.out file (or include it with your bug report).

"Reboot" the NFSv4 server without shutting down the machine

Just shut down rpc.nfsd and start it again.

I get different results when mounting via NFSv3 and NFSv4

Find a file that is differing between v3 and v4, and look at the output from the `stat` utility.

Or use `ls -lid --type-style=full-iso` and `ls -lid --time=ctime --time-style=full-iso` if you don't have stat.

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