How to Troubleshoot NFS Mount Timeout Issues in Linux

Network File System (NFS) is one of the most reliable ways to share files between Linux systems.

But like any network-based service, it can sometimes fail when you need it most.

One of the most common headaches administrators face is the dreaded NFS mount timeout error.

If you’ve ever run into:

mount.nfs: mount to NFS server 'server:/share' failed: timed out, giving up

or simply:

mount.nfs: Connection timed out

then you know the frustration. The good news?

These problems usually come down to connectivity or service issues that can be fixed with a few systematic checks. Let’s walk through the troubleshooting process step by step.

Table of Contents

Step 1: Check the Basics — Can You Reach the Server?

First, make sure the client can even talk to the server.

ping 192.168.1.10 -c3

Example output:

PING 192.168.1.10 (192.168.1.10) 56(84) bytes of data.
64 bytes from 192.168.1.10: icmp_seq=1 ttl=64 time=0.350 ms
64 bytes from 192.168.1.10: icmp_seq=2 ttl=64 time=0.280 ms
64 bytes from 192.168.1.10: icmp_seq=3 ttl=64 time=0.290 ms

--- 192.168.1.10 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms

If you get replies like this, connectivity is fine. If you see 100% packet loss, the server may be down or blocked by a firewall.

Next, check whether the NFS-related ports are open.

nc -v 192.168.1.10 2049

Successful output:

Ncat: Connected to 192.168.1.10:2049.
Ncat: 0 bytes sent, 0 bytes received in 0.01 seconds.

If instead you see:

Ncat: Connection timed out.

then the NFS service might not be listening, or a firewall is blocking the port.

Step 2: Verify Services on the Server

Now, let’s confirm whether the server is actually running the right services.

rpcinfo -p 192.168.1.10

Example output:

   program vers proto   port  service
    100000    4   tcp    111  portmapper
    100003    3   tcp   2049  nfs
    100005    1   tcp  20048  mountd
    100021    1   tcp  32819  nlockmgr

Here’s what this means:

portmapper (111) → required for mapping RPC services.
nfs (2049) → the NFS service itself.
mountd → handles mount requests.
nlockmgr → manages file locking.

If you don’t see nfs or mountd in the list, the server isn’t ready to serve NFS clients.

Step 3: Dig Deeper with Packet Captures

If the server looks fine but the client still times out, check what’s happening on the wire.

Run a packet capture while trying to mount:

tcpdump -s0 -i eth0 host 192.168.1.10 \\
  -w /tmp/2025-08-28-client-nfs.pcap &
mount -t nfs 192.168.1.10:/data /mnt -vvv
pkill tcpdump

The -vvv in the mount command shows extra details. For example:

Verbose output:

mount.nfs: trying text-based options 'vers=3,addr=192.168.1.10,clientaddr=192.168.1.20'
mount.nfs: mount(2): Connection timed out
mount.nfs: trying 192.168.1.10 prog 100003 vers 3 prot TCP port 2049
mount.nfs: portmap query failed: RPC: Remote system error - No route to host

From this, you learn two things:

The client is trying NFSv3.
It fails when talking to the server’s portmapper.

That’s a strong sign the problem is either firewall rules or the rpcbind service missing on the server.

Wrapping Up

When NFS mount timeouts occur, it’s tempting to assume the client is broken. But more often than not, the root cause is either a network block or missing services on the server.

Here’s your quick checklist with expected outputs: