If you get the error "NFS4 mount Error reason given by server: No such file or directory" when trying to mount an NFS4 filesystem on a Linux system, it means that the NFS server is unable to find the export that you are trying to mount.
There are a few possible reasons for this error:
The export does not exist on the NFS server. Make sure that you are specifying the correct export name when you run the mount command. You can use the showmount command on the NFS server to list the available exports.
The export is not configured to allow access from your client system. Check the /etc/exports file on the NFS server to see if the export is configured to allow access from your client system. If it is not, you will need to add an entry to the /etc/exports file to allow access.
The NFS server is not running. Make sure that the NFS server is running and that it is listening on the correct ports. You can use the rpcinfo command to check the status of the NFS server.
There is a firewall blocking access to the NFS server. If there is a firewall between the client and the server, make sure that it is configured to allow access to the NFS server on the appropriate ports.
If you are still having trouble after trying these steps, you may want to check the logs on the NFS server for more information about the error. The /var/log/syslog file or the /var/log/messages file may contain more details about the problem.