# NFS troubleshooting
Problem1: Stale NFS File handle
Sample Error Messages - NFS Error 70Error Explanation:
A “stale NFS file handle” error message can and usually is caused by the following events:
- A certain file or directory that is on the NFS server is opened by the NFS client
- That specific file or directory is deleted either on that server or on another system that has access to the same share
- Then that file or directory is accessed on the client
Resolution Tips
- Check connectivity to the storage system (server)
- Check mount point
- Check client vfstab or fstab as relevant
- Check showmount –e filerx from client
- Check exportfs from command line of the storage system
- Check storage system /etc/exports file
Problem2: NFS server not responding
NFS Server (servername) not respondingError Explanation: NFS client hangs, mount hangs on all clients
Resolution Tips
- Use ping to contact the hostname of the storage system (server) from client
- Use ping to contact the client from the storage system
- Check ifconfig from the storage system
- Check that the correct NFS version is enabled
- Check all nfs options on the storage system
- Check /etc/rc file for nfs options
- Check nfs license
Problem3: Permission denied
nfs mount: mount: /nfs: Permission deniedError Explanation: Permission is not there but trying to access NFS share from server
Resolution Tips
- Check showmount –e filername from client
- Try to create a new mountpoint
- Check exportfs at the storage system command line to see what system is exporting
- Check auditlog for recent exportfs –a
- Check the /etc/log/auditlog for messages related to exportfs
- Check the storage path with exportfs –s
- Check whether the client can mount the resource with the exportfs –c command
- Flush the access cache and reload the exports, then retry the mount
Problem4: Network Performance Slow
Poor NFS read and/or write performanceError Explanation: End user is feeling the slowness
Resolution Tips
- Check sysstat 1 for nfs ops/sec vs. kbs/sec
- Check parameters on network card interface (NIC) with ifconfig –a
- Check netdiag
- Check network condition with ifstat –a; netstat –m
- Check client side network condition
- Check routing table on the storage system with netstat
- Check routing table on the client
- Check perfstat.sh
- Check throughput with sio_ntap tool
- Check rsize and wsize
- Consider configuring jumbo frames (entire path must support jumbo frames)
Problem5: RPC not responding
RPC: Unable to receive or RPC:Timed outResolution Tips
- Use ping to contact the storage system (server)
- From storage system, use ping to contact client
- Check mountpoint
- Check showmount –e filerX from client
- Verify name of directory on the storage system
- Check exportfs to see what the storage system is exporting
- Use the "rpcinfo -p filerx" command from the client to verify that the RPCs are running
Problem6: No Space Left On Disk
No space left on disk errorResolution Tips
- Check df for available disk space
- Check for snapshot overruns
- Check quota report for exceeded quotas
Excellent documents, appreciated efforts.!!
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