krb5 mount with large group membership

[Richard Smits <R.Smits@tudelft.nl>]

Hello list,

I am running into a problem. Perhaps someone understands what is 
happening here. I will explain.

I have a Redhat 5.4 client that is accessing a nfs export on a NFS 
server. (Redhat 6.1)

Our KDC is a Windows AD.

The client is using samba-winbind. If a user is a member of 23 groups or 
lower, I can access the export. If a user is a member of more groups, 
the mount fails with a "Permission denied"

mount /data
-bash-3.2$ cd /data
-bash: cd: /data: Permission denied

Thew odd thing is if I try a mount to our Netapp filer with also a krb5 
export, there is no problem.

This has to do something with the ticket size in combination with 
memberships to a large number of groups.

So what must i do to get this Redhat server working with this setup ? It 
seems that Netapp did something to get this working ?

Does this sound familiar to anyone, or should i provide more information ?

Versions server side :
nfs-utils-1.2.3-7
krb5-workstation-1.9-9

Greetings ... Richard Smits