Comment 12 for bug 791588

I'm continuing to dig down on this one since it is still biting. The one thing that is certain is that with the patch applied the error from rpc.idmapd doesn't appear in the syslog. Here's logging *without* the patch, using the archive packages.

Working on Precise amd64.

$ apt-cache policy nfs-common
nfs-common:
  Installed: 1:1.2.5-3ubuntu3
  Candidate: 1:1.2.5-3ubuntu3

/etc/fstab contains:

10.254.251.1:/Library /home/all/Library nfs4 _netdev,auto,user 0 0

I wrapped /usr/sbin/rpc.idmapd and blkmapd with shell scripts to capture their launch and environment at boot time into /var/log/rpc.log

$ cat /var/log/rpc.log
rpc.idmapd called from parent PID 1
TERM=linux
PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin
PWD=/
SHLVL=1
UPSTART_INSTANCE=
UPSTART_EVENTS=local-filesystems
UPSTART_JOB=idmapd
PIPEFS_MOUNTPOINT=/run/rpc_pipefs
_=/usr/bin/env

Sep 2 16:01:23 hephaestion rpc.idmapd.real[3869]: libnfsidmap: using domain: lan.eddie.tj
Sep 2 16:01:23 hephaestion rpc.idmapd.real[3869]: libnfsidmap: Realms list: 'LAN.EDDIE.TJ'
Sep 2 16:01:23 hephaestion rpc.idmapd.real[3869]: libnfsidmap: loaded plugin /lib/libnfsidmap/nsswitch.so for method nsswitch
Sep 2 16:01:23 hephaestion rpc.idmapd.real[3880]: Expiration time is 600 seconds.
Sep 2 16:01:23 hephaestion rpc.idmapd.real[3880]: Opened /proc/net/rpc/nfs4.nametoid/channel
Sep 2 16:01:23 hephaestion rpc.idmapd.real[3880]: Opened /proc/net/rpc/nfs4.idtoname/channel
Sep 2 16:01:23 hephaestion rpc.idmapd.real[3880]: main: open(/var/lib/nfs/rpc_pipefs/nfs): No such file or directory

which confirms the use of the old path.

I ran idmapd with strace to see why it is using that path and found this:

...
5026 open("/etc/idmapd.conf", O_RDONLY) = 3
...
5026 open("/var/lib/nfs/rpc_pipefs/nfs", O_RDONLY) = -1 ENOENT (No such file or directory)

The idmapd.conf is:

$ cat /etc/idmapd.conf
[General]

Verbosity = 0
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = lan.eddie.tj

[Mapping]

Nobody-User = nobody
Nobody-Group = nogroup

So, "Pipefs-Directory" is the culprit. I don't know when that was set but it is obviously the reason for the issue.

I think the reason that the patched 'blkmapd' solves it is because I build and install updated packages, and the postinst job changes the idmapd.conf file.

I found this which seems to indicate a package upgrade issue but I wasn't notified:

-rw-r--r-- 1 root root 385 Apr 18 10:54 /etc/idmapd.conf.merge-error

[General]

Verbosity = 0
<<<<<<< Current
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = lan.eddie.tj
||||||| Older
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = localdomain
=======
Pipefs-Directory = /run/rpc_pipefs
# set your own domain here, if id differs from FQDN minus hostname
# Domain = localdomain
>>>>>>> New

[Mapping]

Nobody-User = nobody
Nobody-Group = nogroup
/etc/idmapd.conf.merge-error (END)