NFSv4 Kernel-server requires 2x manual restart after reboot? Maybe a timing problem?

[Ben DJ <bendj095124367913213465@gmail.com>]

I've installed NFSv4 as nfs-kernel-server.  I'm slowly figuring out
how to get it to configured and working.

After a system reboot, if I try to mount an export,

	mount -t nfs4 192.168.1.2:/test /mnt/test

it just "sits there", never mounting.

So I 1st check what's running,

	ps ax | egrep -i "idmapd|mountd|statd|nfsd|sm-notify"
	 3731 ?        Ss     0:00 /usr/sbin/rpc.idmapd
	 3732 ?        Ss     0:00 /usr/sbin/rpc.idmapd
	 3753 ?        Ss     0:00 /usr/sbin/rpc.statd --no-notify
	 3758 ?        S<     0:00 [nfsd4]
	 3759 ?        S<     0:00 [nfsd]
	 3760 ?        S<     0:00 [nfsd]
	 3761 ?        S<     0:00 [nfsd]
	 3762 ?        S<     0:00 [nfsd]
	 3772 ?        Ss     0:00 /usr/sbin/rpc.mountd

and that looks OK.

After some experiments, I've discovered if I CTRL-C the mount attempt
and restart the server TWICE,

	service nfsserver restart
		Shutting down kernel based NFS server: nfsd statd mountd
                                                done
		Starting kernel based NFS server: idmapdexportfs: Warning: /nfs/test
does not support NFS export.
		 mountd statd nfsd sm-notify
                                                done
	
	service nfsserver restart
		Shutting down kernel based NFS server: nfsd statd mountd
                                                done
		Starting kernel based NFS server: idmapd mountd statd nfsd sm-notify
                                                done

Notice that the 2nd time the "idmapd" appears to be re-started.

then repeat the mount attempt,

	mount -t nfs4 192.168.1.2:/test /mnt/test

it now works.

Checking what's running again,

	ps ax | egrep -i "idmapd|mountd|statd|nfsd|sm-notify"
	
	 3731 ?        Ss     0:00 /usr/sbin/rpc.idmapd
	 3732 ?        Ss     0:00 /usr/sbin/rpc.idmapd
	 5213 ?        S<s    0:00 /usr/sbin/rpc.mountd
	 5216 ?        S<s    0:00 /usr/sbin/rpc.statd --no-notify
	 5221 ?        S<     0:00 [nfsd4]
	 5222 ?        S<     0:00 [nfsd]
	 5223 ?        S<     0:00 [nfsd]
	 5224 ?        S<     0:00 [nfsd]
	 5225 ?        S<     0:00 [nfsd]

It all looks the same as before.  Notice that the rpc.idmapd PIDs are
the same, even though the "service nfsserver restart" 2nd time around
looked like it restarted it.

I don't really understand what the 2X nfsserver restart does.  There
clearly IS an effect. And it looks like it has to do with idmapd.

I can say that

	service nfsserver stop
	service nfs stop
	service quotad stop
	service rpcbind stop
	umount -a
	mount  -a
	service rpcbind start
	service quotad start
	service nfs start
	service nfsserver start

often gives me similar errors,

	Warning: /nfs/test does not support NFS export

that go away if I make sure there's a delay after starting nfs,

	service nfs start && sleep 5
	service nfsserver start

Maybe there's some sort of timing problem on startup?

Any clues?

BenDJ