Trying to understand: CH3SNAS & NFS = Help needed !

I’ve written earlier a simple howto for users with a CH3SNAS to work with NFS. UNFS is a user space implementation of the NFSv3 protocol. This is working flawlessly on the CH3SNAS with various Linux PC’s I am running (CentOS, Debian, Linux Embedded device etc.. )

but for a VMware implementation I need the READDIRPLUS procedure which is not available in UNFS. So I need to run Kernel-NFS on the CH3SNAS

Fonz fun_plug is providing Kernel NFS (enabled in the CH3SNAS) and UNFS. Installation is easy and almost fool proof.

The issue is following: on all my linux boxes (CentOS, Debian etc.. ) I get following message:

mount: mount to NFS server ‘’ failed: timed out (retrying).

  • rcpinfo -p gives all correct info
  • showmount -e gives all correct exports
  • rpcinfo -u gives:

program 100005 version 1 ready and waiting
program 100005 version 2 ready and waiting
program 100005 version 3 ready and waiting

  • Showmount -a gives the mount points I ‘tried’ to use:

All mount points on

and even syslogd gives on the NFS server (CH3SNAS):

Jun 12 18:33:07 DEVELOPMENT daemon.notice mountd[1868]: authenticated mount request from for /mnt/HD_a2 (/mnt/HD_a2)

  • Portmap is running at server and client!!

I am totally not understanding why I get time-outs. I do not have a firewall, I do not use iptables. Today I tried in another environment the same: always the error:

mount: mount to NFS server ‘’ failed: timed out (retrying).

suddenly here at home after about 20 minutes trying to mount the NFS share, the NFS server has been mounted on my local system. But when umounting and mounting again I have again same situation. In my work environment it was totally not possible (standard Debian setup and a CentOS configuration) to have the NFS share mounted. Although it is similar setup ..

So although al tools tells me that everything is correct: I am not getting any mount :-(

Is there anyone with enough NFS knowledge who can tell me why the NFS share is not mounted?

9 thoughts on “Trying to understand: CH3SNAS & NFS = Help needed !

  1. Delekhan says:

    I had the same problems with my CH3SNAS. Try specifying NFSv3 or NFSv2 in commandline. This litte tweak speeds up mounting a LOT. Further, try adjusting rsize and wsize on the client-side to get out maximum speed.

    €: Are you using an old firmware? I can remember that NFSv3 was broken in the earlier v1.03 ones…


  2. Delekhan says:


    here is my fstab entry that works with the CH3SNAS: / nfs rw,hard,intr,rsize=32768,wsize=32768,tcp,async,nfsvers=3 0 0

    and here is my menu.lst for Grub in case you need it:
    # (0) Arch Linux
    title Arch Linux
    root (hd0,0)
    kernel /vmlinuz26 video=i810fb:vram:16,xres:1366,yres:768,hsync1:30,hsync2:85,vsync1:60,vsync2:60,accel,mtrr root=/dev/nfs nfsroot=,v3 ip=dhcp

    I hope this hlps,

  3. Thanks Markus..
    your line is working with mount -a ..but..

    still one time:
    mount: mount to NFS server failed: timed out (retrying).
    I see…
    it’s not mounted in a split second what you would expect…

  4. Delekhan says:

    So this error message is only being displayed once? If so and the drive mounts a second later – ignore it ;-) If not how long does it take now to mount the drive?

    Anyway, you could try to edit rpc_nfsd_flags=”8″ to 16 in /ffp/start/ to have a better response time of the NFS Server. I did this and it speeded up NFS quite a bit.


  5. sblob says:

    Identified problem and fixed it.
    Well, this post is way too old, but the solution might be of interest for new users also…
    it was a firewall related issue: iptables was set to allow TCP communication from mounter to nfs server, but tcpdump showed some UDP traffic that was not being accepted.
    I allowed both UDP and TCP traffic and it worked immediately.
    Hope this helps.

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