[ADMIN] real and effective user ids must match

[Liustech]

My postgres can not start up,  I get this error message:   postmaster successfully started /usr/bin/postmaster: real and effective user ids must match   and   Sep 12 14:18:26 TWeb su(pam_unix)[6683]: session opened for user postgres by (uid=0) Sep 12 14:18:26 TWeb su(pam_unix)[6683]: session closed for user postgres Sep 12 14:18:29 TWeb su(pam_unix)[6702]: session opened for user postgres by (uid=0) Sep 12 14:18:29 TWeb su(pam_unix)[6702]: session closed for user postgres Sep 12 14:18:30 TWeb postgresql: Starting postgresql service:  failed what is happen and how to fix it?   regards David