RHEL6: If /proc/net/rpc/auth.unix.gid/channel is referred, the RPC time-out is generated.

Issue

• Running sosreport on the NFS server causes NFS server to temporarily not respond to NFS client.
• NFS server TCP ACKs NFS client requests, then silently drops them, never responding at the NFS layer.
• NFS times out periodically with the following message seen in the log

kernel: nfs: server nfsserver not responding, still trying

• If /proc/net/rpc/auth.unix.gid/channel is referred, the RPC time-out is generated e.g.

     # df
     Filesystem           1K-blocks      Used Available Use% Mounted on
     /dev/vda5             17906468  10171684   6825168  60% /
     tmpfs                  1027344        88   1027256   1% /dev/shm
     /dev/vda1               198337     28339    159758  16% /boot
     /dev/vda2              2015824     35812   1877612   2% /work
     df: `/mnt/nfs': Input/output error