Monday, August 22, 2016

Netapp NFS Issues Troubleshooting tips and steps Ultimate Guide

# NFS troubleshooting

Problem1: Stale NFS File handle

Sample Error Messages - NFS Error 70

Error Explanation:

A “stale NFS file handle” error message can and usually is caused by the following events:
  1. A certain file or directory that is on the NFS server is opened by the NFS client
  2. That specific file or directory is deleted either on that server or on another system that has access to the same share
  3. Then that file or directory is accessed on the client
  A file handle usually becomes stale when a file or directory referenced by the file handle on the client is removed by another host, while your client is still holding on to an active reference to that object.

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 responding

Error 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 denied

Error 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 performance

Error 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 out

Resolution 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 error

Resolution Tips

  • Check df for available disk space
  • Check for snapshot overruns
  • Check quota report for exceeded quotas

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