"Permission denied", while accessing the Files on a NFS share from Solaris clients

We got an issue where customer was running an automated process on the Unix NFS clients that creates a report and then copies the content on the NFS share. The process was running fine until last few days.

We had User name mapping set through ADlookup. So we checked the setting and NFS driver version. Everything seems to be in place.

On the UNIX side, we were still getting an error “RPC authentication error”.

So we checked the user’s properties in AD. UID and GID were populated with correct value. Then from the command prompt we ran the command:

‘net user <user-name>’ and found the User’s account to be locked. This was creating the authentication errors.

So what happens is, when the credentials from the Unix clients comes for authentication (UID & GID) against the Windows SAM account name, it would not get a token from the Windows side and hence on the Unix side you will get permission denied.