FC19 - Enable NFSv2

[Matthias81]

Hello,

I have a fresh FC19 installation (MATE Desktop) where I try to enable NFSv2 to boot
an embedded board.

NFS is basically running, but only v3 and v4:

$ rpcinfo -p
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 3 tcp 2049 nfs_acl
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs
100227 3 udp 2049 nfs_acl
100021 1 udp 38559 nlockmgr
100021 3 udp 38559 nlockmgr
100021 4 udp 38559 nlockmgr
100021 1 tcp 56237 nlockmgr
100021 3 tcp 56237 nlockmgr
100021 4 tcp 56237 nlockmgr
100011 1 udp 875 rquotad
100011 2 udp 875 rquotad
100011 1 tcp 875 rquotad
100011 2 tcp 875 rquotad
100005 1 udp 20048 mountd
100005 1 tcp 20048 mountd
100005 2 udp 20048 mountd
100005 2 tcp 20048 mountd
100005 3 udp 20048 mountd
100005 3 tcp 20048 mountd
100024 1 udp 55122 status
100024 1 tcp 39133 status

How can I enable the protocol version 2?

Best regards,

Matthias

[stevea]

Interesting - I get this ...

100003 2 tcp 2049 nfs
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 2 tcp 2049 nfs_acl
100227 3 tcp 2049 nfs_acl
100003 2 udp 2049 nfs
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs

What's in /etc/sysconfig/nfs ?

[Matthias81]

The /etc/sysconfig/nfs file contains

#
# Optinal options passed to rquotad
RPCRQUOTADOPTS=""
#
# Optional arguments passed to in-kernel lockd
#LOCKDARG=
# TCP port rpc.lockd should listen on.
#LOCKD_TCPPORT=32803
# UDP port rpc.lockd should listen on.
#LOCKD_UDPPORT=32769
#
# Optional arguments passed to rpc.nfsd. See rpc.nfsd(8)
RPCNFSDARGS=""
# Number of nfs server processes to be started.
# The default is 8.
RPCNFSDCOUNT=8
# Set V4 grace period in seconds
#NFSD_V4_GRACE=90
#
# Optional arguments passed to rpc.mountd. See rpc.mountd(8)
RPCMOUNTDOPTS=""
#
# Optional arguments passed to rpc.statd. See rpc.statd(8)
STATDARG=""
#
# Optional arguments passed to rpc.idmapd. See rpc.idmapd(8)
RPCIDMAPDARGS=""
#
# Optional arguments passed to rpc.gssd. See rpc.gssd(8)
RPCGSSDARGS=""
# Enable usage of gssproxy. See gssproxy-mech(8).
GSS_USE_PROXY="no"
#
# Optional arguments passed to rpc.svcgssd. See rpc.svcgssd(8)
RPCSVCGSSDARGS=""
#
# To enable RDMA support on the server by setting this to
# the port the server should listen on
#RDMA_PORT=20049
#
# Optional arguments passed to blkmapd. See blkmapd(8)
BLKMAPDARGS=""

To install / start NFS I did the following:

$ yum -y install nfs-utils

add a line to /etc/exports

$ systemctl start rpcbind.service
$ systemctl start nfs-server.service
$ systemctl start nfs-lock.service
$ systemctl start nfs-idmap.service

[Matthias81]

If I enable the services and reboot I get the following output:

$ systemctl enable rpcbind.service
$ systemctl enable nfs-server.service
$ systemctl enable nfs-lock.service
$ systemctl enable nfs-idmap.service

$ rpcinfo -p
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 3 tcp 2049 nfs_acl
100003 3 udp 2049 nfs
100003 4 udp 2049 nfs
100227 3 udp 2049 nfs_acl
100021 1 udp 38559 nlockmgr
100021 3 udp 38559 nlockmgr
100021 4 udp 38559 nlockmgr
100021 1 tcp 56237 nlockmgr
100021 3 tcp 56237 nlockmgr
100021 4 tcp 56237 nlockmgr

But no NFSv2 ...

[marko]

does rpcinfo -s show '2' as a version in the second column?

Does it help to add the nfsvers=2 option in your /etc/fstab entry for that mount ? (see "man nfs" )

[Matthias81]

Do you mean I should add on the server an entry in the fstab for the NFS export?
I never did that in the past. (On e.g. Debian)

Or do you mean on the client? The client is a arm linux kernel which mounts the root filesystem via NFS.
(There is also no fstab entry. The parameters are given on the kernel commandline.)

[I try to port/move my development Environment from Debian to Fedora.]

[Matthias81]

Here is the output of rpcinfo -s

$ rpcinfo -s
program version(s) netid(s) service owner
100000 2,3,4 local,udp,tcp,udp6,tcp6 portmapper superuser
100003 4,3 udp6,tcp6,udp,tcp nfs superuser
100227 3 udp6,tcp6,udp,tcp nfs_acl superuser
100021 4,3,1 tcp6,udp6,tcp,udp nlockmgr superuser

[Matthias81]

Has anyone an idea why NFSv2 is not started ?

[jimbo333]

My NFSv2 capable server was working until I updated to the latest updates today. I suspect an update along the way broke NFSv2 mounts, if I try:

mount -o nolock,vers=2,tcp <ip>:/path /mnt

I just get the following error:

mount.nfs: Protocol not supported

This was working yesterday, the only change was I updated the system.

---------- Post added at 01:05 AM ---------- Previous post was at 01:01 AM ----------

It appears like the kernel package broke it:

cat /proc/fs/nfsd/versions
-2 +3 +4 +4.1 -4.2

See this discussion on the kernel lists, it appears to be an upstream issue in nfs-utils

https://lkml.org/lkml/2013/9/26/764


Update: Work-around that works for me, from the above discussion:

I've changed /etc/sysconfig/nfs file as following diff ;
@@ -10,7 +10,7 @@
#LOCKD_UDPPORT=32769
#
# Optional arguments passed to rpc.nfsd. See rpc.nfsd(8)
-RPCNFSDARGS=""
+RPCNFSDARGS="-V 2"

Then. run nfs server again...

# systemctl restart nfs-server.service

# cat /proc/fs/nfsd/versions
+2 +3 +4 +4.1 -4.2

Everything works after that. Sorry for spamming the post so quickly, but I seem to have found a solution Can others confirm then add solved if it works?

[lemeza]

jimbo333,

Thanks a bunch! Your solution saved my keester! I been trying to solve this for a week now, with now luck. But, I changed the /etc/sysconfig/nfs file as you described and did a reboot, now my clien development board can mount an FS over NFSv2 on my Fedora 19 box.

Thanks again!

[DBelton]

Just FYI

I believe that they are going to stop compiling the kernel with NFSv2 in Fedora 20. You can still compile the kernel yourself and build the modules, but as far as the plain Fedora kernel, it's going to support NFSv3 and NFSv4 only.

[CassiusActarus]

Hi There,

I try to setup an nfs server to boot a diskless single board computer.
I ran into the exact issue described above using Fedora 22. rpcinfo -p show that only ver 3 and 4 of nfs are running.

I try the fixed given here to add the -V 2 option to in the /etc/sysconfig/nfs file, but with no effect. I am not sure if this file is actually used any more, as putting any kind of arguments does not affect the restart of the nfs service (systemctl restart nfs).

Following on this:

I believe that they are going to stop compiling the kernel with NFSv2 in Fedora 20. You can still compile the kernel yourself and build the modules, but as far as the plain Fedora kernel, it's going to support NFSv3 and NFSv4 only.

I search on the web about this and didn't found any other source mentioning this drop in the support of NFSv2. Is that true? Is there instruction on how to rebuild the nfs kernel module (that start to be out of my range of competence, so sorry if I use incorrect wording).

Thanks for your help!

[CassiusActarus]

Hi leonpollak

I started again this morning is a fresher mind and the assurance it could work! I found the issue. The problem was how I restarted the nfs service on the server after editing the /etc/sysconfig/nfs file.

On FC22 you need to restart nfs with:
# systemctl restart nfs-config (<- that one actually indicated in etc/sysconfig/nfs, just have to read... )
# systemctl restart nfs
# systemctl restart rpcbind

Once you do that, you got
# cat /proc/fs/nfsd/versions
+2 +3 +4 +4.1 -4.2

The embedded system now mount the NFS partition correctly (but end up in yet another form of kernel panic).

Thanks a lot for your help!