altough LightDM solve the login problem, it's not solution, becouse the NIS user can not shutdown/reboot the computer from the gnome session.
so I switch back to gdm and try the nscd hint .. looks like this solve both problem for me! -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1882034 Title: cannot start X session with NIS account Status in gdm3 package in Ubuntu: Incomplete Status in systemd package in Ubuntu: Incomplete Bug description: When login with a NIS account, X does not start, or more precisely it starts and exits immediately. Only errors in logs is: (EE) systemd-logind: failed to get session: PID 4335 does not belong to any known session X11/gdm login works fine with local accounts. SSH/terminal console login with NIS accounts works fine. /etc/X11/Xwrapper.config: allowed_users=anybody I've seen several reports of such problems under other versions (eg 19.10), but no working solutions was found. It seems that the problem is the same with lightdm. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: gdm3 3.34.1-1ubuntu1 ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30 Uname: Linux 5.4.0-29-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.2 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu Jun 4 08:59:25 2020 InstallationDate: Installed on 2019-11-26 (190 days ago) InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017) SourcePackage: gdm3 UpgradeStatus: Upgraded to focal on 2020-04-24 (40 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1882034/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
