DomU boot NFSD "90-second grace period" is ~ 4-5 minutes, then finishes without problem. How to debug/fix the extended wait?

[dchilton+linux-nfs@bestmail.us]

Hi,

I'm booting a Xen DomU that connects to NFS4 mounts served up by the
Dom0. Fyi,

rpm -qa | egrep -i "^nfs|^kernel"
 nfs-kernel-server-1.2.3-11.16.1.x86_64
 nfsidmap-0.23-13.1.x86_64
 nfs-client-1.2.3-11.16.1.x86_64
 kernel-xen-2.6.37.6-0.7.1.x86_64

@ DomU launch, it gets to the NFSv4 'stuff',

	...
	[   11.533498] EXT4-fs (xvda1): mounted filesystem with ordered
	data mode. Opts: acl,user_xattr,barrier=1
	[   11.579889] EXT4-fs (xvdd): mounted filesystem with ordered
	data mode. Opts: acl,user_xattr,journal_checksum,barrier=1
	[   15.237650] microcode: Microcode Update Driver: v2.00-xen
	<tigran@aivazian.fsnet.co.uk>, Peter Oruba
	[   24.271451] RPC: Registered udp transport module.
	[   24.271469] RPC: Registered tcp transport module.
	[   24.271479] RPC: Registered tcp NFSv4.1 backchannel transport
	module.
	[   24.340308] FS-Cache: Loaded
	[   24.554720] Installing knfsd (copyright (C) 1996
	okir@monad.swb.de).
	[   24.555025] FS-Cache: Netfs 'nfs' registered for caching
	[   25.239401] NFSD: Using /var/lib/nfs/v4recovery as the NFSv4
	state recovery directory
	[   25.245234] NFSD: starting 90-second grace period

and simply, quietly sits there ~4-5 minutes.  Then, without any further
fanfare, the boot completes.

	Welcome to openSUSE 11.4 "Celadon" - Kernel 2.6.37.6-0.7-xen
	(xvc0).
	
	test login:

At this point the DomU is up.  All the NFS mounts are mounted.  Nothing
seems amiss.

Clearly, the 4-5 minute wait isn't normal.

I suspect that there's some sort of settling/locking issue, but I don't
know how to verify or debug the source of the problem.

Any pointers as to what to start looking at?

Thanks

DCh