Force unmount of NFS-mounted directory

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If the NFS server disappeared and you can't get it back online, one trick that I use is to add an alias to the interface with the IP of the NFS server (in this example, 192.0.2.55).

Linux

The command for that is something roughly like:

ifconfig eth0:fakenfs 192.0.2.55 netmask 255.255.255.255

Where 192.0.2.55 is the IP of the NFS server that went away. You should then be able to ping the address, and you should also be able to unmount the filesystem (use unmount -f). You should then destroy the aliased interface so you no longer route traffic to the old NFS server to yourself with:

ifconfig eth0:fakenfs down 

 umount -f -l /my/mount/dir

rpc.nfsd: unable to set any sockets for nfsd

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Error: When you install and restart NFS service you will get an error “rpc.nfsd unable to set any sockets for nfsd”
Root cause: This problem may occur due to rpcbind service is not working or the app is not been installed on the server.
Solution:
1. Check the rpcbind service works perfectly by:- #rpcbinfo -p
2. If it throws an error by “rpcinfo: can’t contact portmapper: RPC: Remote system error – No such file or directory”
3. Then we need to install the rpc package by
3a. # yum install avahi
Installing : libdaemon-0.14-1.fc13.i686
Installing : avahi-0.6.27-1.fc14.i686
4. Then restart rpcbind service and check # rpcinfo -p status
5. Then restart nfs service.
6. Check the NFS daemon are avaiable in all run levels by #chkconfig nfs –list
7. Now restart the NFS service where the service starts successfully.