On Fri, Sep 15, 2006 at 11:13:06AM +0800, david.lao@xxxxxxxxxxxxxxxx wrote: > Thanks, I will try to upgrade new viersion, the ouput of <su -l postgres -s /bin/sh -c "/usr/bin/pg_ctl -D $PGDATA -p /usr/bin/postmaster start> is > < > postmaster successfully started > /usr/bin/postmaster: real and effective user ids must match The postmaster still thinks it's running setuid; this error appears to be coming from backend/main/main.c (excerpt from the 7.2.2 source code): if (getuid() != geteuid()) { fprintf(stderr, gettext("%s: real and effective user ids must match\n"), argv[0]); exit(1); } Can you start the postmaster without using pg_ctl? Please post the output of the following commands (make sure PGDATA is set for the second one): su -l postgres -s /bin/sh -c id su -l postgres -s /bin/sh -c "/usr/bin/postmaster -D $PGDATA" What OS are you running? > the problem start after I restart the postgres service, there are nothing > change in postmaster since last time. When was the last time you successfully started the postmaster the same way you're trying now? How long had you been running PostgreSQL without any problems? If it used to work then something has changed. -- Michael Fuhr