We got sometimes a kernel messages with nfsv4 shares

NFSv4 callback reply buffer overflowed

Apr 29 11:45:47 server01 kernel: [ 193.283103] RPC: Registered tcp NFSv4.1 backchannel transport module.
Apr 29 14:21:35 server01 kernel: [ 9525.728830] NFSv4 callback reply buffer overflowed!
How big is the reply buffer?
Can we increase the buffer?

Is this a problem on client or on server side?

The nfs server is a netapp filer (ontap 8.1) which have read delegation (nfs 4.1) feature on.

kernel version:
Linux ams01 3.0.101-0.47.52-default #1 SMP Thu Mar 26 10:55:49 UTC 2015 (0e3c7c8) x86_64 x86_64 x86_64 GNU/Linux

Repository: SLES 11 SP3 Updates
Name: nfs-client
Version: 1.2.3-18.38.41.1
Arch: x86_64
Vendor: SUSE LINUX Products GmbH, Nuernberg, Germany