I tested using nfs version 3 on my lab system, and it works fine.

[root@server2 ~]# tail -1 /etc/mtab

server1:/nfs /nfs nfs rw,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=,mountvers=3,mountport=20048,mountproto=udp,local_lock=none,addr= 0 0

[root@server2 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.4 (Maipo)
[root@server2 ~]#

However. when I do the same thing on Azure, it fails. I followed this guide

Link to vers 3 nfs

But when I mount it using version 3, it gives below error

mount -vv  -t nfs -o vers=3 server1:/appl /wbr

mount.nfs: timeout set for Thu Aug  1 02:38:02 2019
mount.nfs: trying text-based options 'vers=3,addr='
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying prog 100005 vers 3 prot UDP port 20048
mount.nfs: portmap query retrying: RPC: Timed out

Version 4 works just fine, but version 3 does not!

Any ideas?

  • Stop using version 3, of course. It was obsolete almost 20 years ago. – Michael Hampton Aug 1 '19 at 3:48
  • i know, but MUST use it for our legacy app which works best on version 3 – david bob Aug 1 '19 at 5:18
  • Does showmount -e <server> work? Are the necessary ports op in the firewalls between the systems (portmapper and whatever ports are used for the nfs services) ? – HBruijn Aug 1 '19 at 6:40
  • i can mount it using version 4, that means ports are open and does not look like firewall, i have disabled both firewalld/iptables – david bob Aug 1 '19 at 7:36
  • Did you check your Azure security group? – Michael Hampton Aug 1 '19 at 8:00

The vendor provides NFSv3 support in RHEL7 (see Introduction to NFS).

Please do the following checks:

1) Ensure NFSv3 support is enabled in the /etc/sysconfig/nfs file:


To prevent clients from using NFSv4, add the setting


2) Check if NFS daemons are running on the NFS server:

# service nfs status
# service portmap status

3) Check if your NFS server in Azure is available from the client system via NFS network ports:

  • port 111 (TCP and UDP);
  • port 2049 (TCP and UDP)

with any tool you prefer, e.g.:

# telnet nfs_server_ip_addr 2049
# nmap -sU -p 111,2049 nfs_server_ip_addr
# nmap -sT -p 111,2049 nfs_server_ip_addr

4) Check if existing mounts are visible from the client system:

# showmount -e nfs_server_name
  • 1,2) nfs is working on version 4, so everything is in place, I can telnet, nmap gives below output PORT STATE SERVICE 111/udp open rpcbind 2049/udp open|filtered nfs 3)showmount does not show anything, but still can mount using version 4 – david bob Aug 1 '19 at 8:53
  • Is NFS3 support enabled in the /etc/sysconfig/nfs file? NFS3_SERVER_SUPPORT="yes" – mebius99 Aug 1 '19 at 10:01

Got it working!

I put this in the /etc/sysconfig/nfs file







systemctl restart nfs-config

Then I opened the above ports tcp/udp on azure and was able to mount it!

Thanks to everyone for their support!

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