Limitations on the number of groups in the NFS structure

On systems that use NFS Version 2 or 3, users cannot be a member of more than 16 groups without complications.

Groups are defined by the groups command. If a user is a member of 17 or more groups, and the user tries to access files owned by the 17th (or greater) group, the system does not allow the file to be read or copied. To permit the user access to the files, rearrange the group order.

The information above describes default behavior. Please see the maxgroups parameter of the mount command for more details.