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Received erroneous SM_UNMON request from

Created by dave. Last edited by dave, 18 years and 34 days ago. Viewed 13,806 times. #2
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Lots of error messages in nfs server syslog like
Received erroneous SM_UNMON request from $SYSTEM for $REMOTESYSTEM

What I Did

Ignore it; it seems harmless, and no one on the internet seems to know really what is going on. Isn't open source grand!

What It Isn't

A quick google turned up this snippet:

Basically it means that your rpc.statd daemon is unaware of a lot of its clients. It is probably failing to save their IP-numbers to disk. Check therefore that the directories /var/lib/nfs/sm, and /var/lib/nfs/sm.bak (or /var/lib/nfs/statd/sm, … on some platforms) are writable by the rpc.statd process.

see original URL >>

One Observation

This cached page from google has some interesting discussion


[NFS] SM_UNMON again -> kernel

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From: Lawrence Ong <> Date: Fri, 11 Jul 2003 16:16:15 +1000

Hi Everybody,

If someone can shed some light on why this annoying message kept appearing, it would be much appreciated. I'm sure a lot of other people out there are getting the same error message.

The Error in Syslog that we continually get is the common:

Received erroneous SM_UNMON request from mymachine for

The error does not break NFS or anything. It's just a rather annoying message that kept on appearing again and again. Looking through the different mailing list did not help. None of the solutions provided refers to kernel 2.4.19-21 or is the reason why it gives that error.


The system that we're using is booting off the kernel 2.4.21 kernel with nfs-utils 1.0.3 on a Debian Woody system. We have also tested this on 2.4.19 and 2.4.20 with and without Trond's NFS (FIXES/ALL) patches. We have also tested the system with nfs-utils version 1.0.0.

We noticed that it is getting that error because in monitor.c, the value generated by NL_MY_NAME(clnt) is Is this suppose to be correct?!

The NFS server contains the IP address, mymachine is the client with the IP address The client mounts the server as such: /mountpath nfs rsize=8192,wsize=8192,nfsvers=3,udp,noatime,hard,intr,bg 0 0


Looking at utils/statd/monitor.c - we have lines that read:

while ((clnt = nlist_gethost(clnt, mon_name, 0))) {

if (matchhostname(NL_MY_NAME(clnt), my_name) &&

This matchhostname never match because NL_MY_NAME(clnt) gives but the my_name variable in sm_unmon_1_svc function is mymachine.


In monitor.c again, in the sm_mon_1_svc function, we have:

struct sm_stat_res *
sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp) {

static sm_stat_res result; char *mon_name = argp->mon_id.mon_name, *my_name = argp->mon_id.my_id.my_name;

… my_name = "";

What the?! my_name is reset to due to some CERT Advisory CA-99.05? Anyhow, lets just ignore that since this is not the main cause of why the error message appears in the first place. Now we're back to the kernel that kept on producing an SM_UNMON RPC to statd.

It looks like this unmon stufff is happening too regularly? Now i'm wondering why it is attempting to UNMON so regularly in the first place?

This brings us back to kernel 2.4.19-21. Why is the kernel's statd client calling statd so regularly for sm_unmon?!!! No, i did not stop the nfs-kernel-server. No, i'm not mounting and unmounting NFS regularly.

Is there something else i should check? I'll start looking at the kernel code while awaiting reply. Any help/suggestions appreciated.

Cheers, Lawrence

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>> Received on 2003-07-11 06:21:04

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