[Pacemaker] nfsv4 grace period

[Dennis Jacobfeuerborn]

Hi,
i have setup a nfsv3 HA cluster before and that works fine but now I'm 
trying to move to v4 and run into problems with the lease grace period.
The grace period on CentOS 6 is 90 seconds and that limits how quickly 
the fail-over can happen. The file /etc/sysconfig/nfs contains a 
variable NFSD_V4_GRACE to control this but it doesn't get applied. The 
reason is that the file /proc/fs/nfsd/nfsv4gracetime is not writable:

[root at nfs1 init.d]# echo 10 > /proc/fs/nfsd/nfsv4gracetime
-bash: echo: write error: Device or resource busy

Does anyone know what the proper way is to reduce this value?

Also the documentation for the "wait_for_leasetime_on_stop" parameter 
for the exportfs resource says this: "Note that when this parameter is 
set, your stop timeout MUST accommodate for the wait period."

Does that mean that I should add 'op stop timeout="15s"' to the resource 
if the grace time is 10s or would that be too short?

Regards,
   Dennis