idmapd doesnt start (wrong rpc_pipefs path)

[Ralph Thesen]

Using NFS4 idmapd is necessary to map the ids of nfs mounts.

/var/log/syslog says:

May 2 14:16:30 anon rpc.idmapd[1250]: main: open(/var/lib/nfs/rpc_pipefs/nfs): No such file or directory
May 2 14:16:30 anon kernel: [ 19.549666] init: idmapd main process (1250) terminated with status 1
May 2 14:16:30 anon kernel: [ 19.549680] init: idmapd respawning too fast, stopped

mount says:

rpc_pipefs on /run/rpc_pipefs type rpc_pipefs (rw,relatime)

Remark: on Lucid it is:

rpc_pipefs on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)

Workaround:

ln -s /run/rpc_pipefs /var/lib/nfs/rpc_pipefs

[Steve Langasek (vorlon)]

You clearly aren't using the Ubuntu version of rpc.idmapd, which does use the /run/rpc_pipefs mountpoint.

[Ralph Thesen (thesen)]

if this is not the Ubuntu version, which version is it?

root@anon:~# which rpc.idmapd
/usr/sbin/rpc.idmapd

root@anon:~# dpkg -S rpc.idmapd
nfs-common: /usr/sbin/rpc.idmapd
nfs-common: /usr/share/man/man8/rpc.idmapd.8.gz

root@anon:~# dpkg -l nfs-common
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Description
+++-=========================-=========================-==================================================================
ii nfs-common 1:1.2.5-3ubuntu3 NFS support files common to client and server

man rpc.idmapd says:
-p path Specifies the location of the RPC pipefs to be path. The default value is "/var/lib/nfs/rpc_pipefs".

[Ralph Thesen (thesen)]

root@anon:~# apt-get source nfs-common
[...]
root@anon:~# grep -nir "/var/lib/nfs/rpc_pipefs" nfs-utils-1.2.5/utils/idmapd/idmapd.c
74:#define PIPEFS_DIR "/var/lib/nfs/rpc_pipefs/"

[Steve Langasek (vorlon)]

You may have the Ubuntu package installed, but that is *not* the Ubuntu rpc.idmapd on your filesystem.

$ strings /usr/sbin/rpc.idmapd |grep pipefs
/run/rpc_pipefs
$ debsums -s nfs-common
$

You may need to reinstall the package.

[Steve Langasek (vorlon)]

Actually, there's another possibility: you may have Pipefs-Directory set to the wrong place in /etc/idmapd.conf. The correct default /etc/idmapd.conf, as shipped by nfs-common, is:

[General]

Verbosity = 0
Pipefs-Directory = /run/rpc_pipefs
# set your own domain here, if id differs from FQDN minus hostname
# Domain = localdomain

[Mapping]

Nobody-User = nobody
Nobody-Group = nogroup

So you may have opted to "keep your version" of the config file on upgrade, which in this particular case results in a broken config.

[Ralph Thesen (thesen)]

You are right, i used the old idmapd.conf. Thx alot.