Getting permission denied error intermittently from Unix clients

Recently we got a case where customer informed that intermittently he is getting access denied error from the Unix clients. This happens while the users from Unix clients are trying to list the content inside the NFS share or read\write into a file.

The environment was:

Windows 2003 R2, 2 node cluster, Windows 2003 SP2 as DC, Solaris as NFS client

During the troubleshooting customer confirmed that he is using Domain users for User name mapping. But he has not installed the component ‘NFS Auth’ on the entire Domain controllers.

Suggested him to install the ‘NFS authentication’ module on all the DC and the reboot them. Also sent him the TechNet document which talks about this:

After installing the ‘NFS authentication module’, all the Domain controllers were rebooted. This resolved the issue. We monitored the Unix clients for couple of weeks and there were no issues related to ‘access denied’