I have problem with starting PostgreSQL 8.4 on Ubuntu 9.10 Server after blackout. When I try to connect to the database it says:

psql: server closed the connection unexpectedly
This probably means the server terminated abnormally before or while processing the request.

When I try to start it by using command

sudo -u postgres /etc/init.d/postgresql-8.4 start
 * Starting PostgreSQL 8.4 database server                               [ OK ]

Netstat output

netstat -tulp
(No info could be read for "-p": geteuid()=1000 but you should be root.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 localhost:postgresql    *:*                     LISTEN      -
tcp        0      0 192.168.1.35:svn        *:*                     LISTEN      -
tcp        0      0 192.168.1.35:http-alt   *:*                     LISTEN      -
tcp        0      0 *:ssh                   *:*                     LISTEN      -
tcp6       0      0 localhost:postgresql    [::]:*                  LISTEN      -
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN      -
udp        0      0 *:bootpc                *:*                                 -

But still don't work so lets restart it

sudo -u postgres /etc/init.d/postgresql-8.4 restart
 * Restarting PostgreSQL 8.4 database server                                     * The PostgreSQL server failed to start. Please check the log output:
2009-11-30 13:39:37 CET LOG:  database system was shut down at 2009-11-30 13:39:33 CET
2009-11-30 13:39:37 CET LOG:  autovacuum launcher started
2009-11-30 13:39:37 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:37 CET LOG:  incomplete startup packet
2009-11-30 13:39:38 CET LOG:  server process (PID 2240) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:38 CET LOG:  terminating any other active server processes
2009-11-30 13:39:38 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:38 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:37 CET
2009-11-30 13:39:38 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:38 CET LOG:  record with zero length at 0/11D464C
2009-11-30 13:39:38 CET LOG:  redo is not required
2009-11-30 13:39:38 CET LOG:  autovacuum launcher started
2009-11-30 13:39:38 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:38 CET LOG:  server process (PID 2248) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:38 CET LOG:  terminating any other active server processes
2009-11-30 13:39:38 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:38 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:38 CET
2009-11-30 13:39:38 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:38 CET LOG:  record with zero length at 0/11D4690
2009-11-30 13:39:38 CET LOG:  redo is not required
2009-11-30 13:39:39 CET LOG:  autovacuum launcher started
2009-11-30 13:39:39 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:39 CET LOG:  server process (PID 2256) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:39 CET LOG:  terminating any other active server processes
2009-11-30 13:39:39 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:39 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:38 CET
2009-11-30 13:39:39 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:39 CET LOG:  record with zero length at 0/11D46D4
2009-11-30 13:39:39 CET LOG:  redo is not required
2009-11-30 13:39:39 CET LOG:  autovacuum launcher started
2009-11-30 13:39:39 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:39 CET LOG:  server process (PID 2264) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:39 CET LOG:  terminating any other active server processes
2009-11-30 13:39:39 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:39 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:39 CET
2009-11-30 13:39:39 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:40 CET LOG:  record with zero length at 0/11D4718
2009-11-30 13:39:40 CET LOG:  redo is not required
2009-11-30 13:39:40 CET LOG:  autovacuum launcher started
2009-11-30 13:39:40 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:40 CET LOG:  server process (PID 2272) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:40 CET LOG:  terminating any other active server processes
2009-11-30 13:39:40 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:40 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:40 CET
2009-11-30 13:39:40 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:40 CET LOG:  record with zero length at 0/11D475C
2009-11-30 13:39:40 CET LOG:  redo is not required
2009-11-30 13:39:40 CET LOG:  autovacuum launcher started
2009-11-30 13:39:40 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:41 CET LOG:  server process (PID 2280) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:41 CET LOG:  terminating any other active server processes
2009-11-30 13:39:41 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:41 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:40 CET
2009-11-30 13:39:41 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:41 CET LOG:  record with zero length at 0/11D47A0
2009-11-30 13:39:41 CET LOG:  redo is not required
2009-11-30 13:39:41 CET LOG:  autovacuum launcher started
2009-11-30 13:39:41 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:41 CET LOG:  server process (PID 2288) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:41 CET LOG:  terminating any other active server processes
2009-11-30 13:39:41 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:41 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:41 CET
2009-11-30 13:39:41 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:41 CET LOG:  record with zero length at 0/11D47E4
2009-11-30 13:39:41 CET LOG:  redo is not required
2009-11-30 13:39:41 CET LOG:  autovacuum launcher started
2009-11-30 13:39:41 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:42 CET LOG:  server process (PID 2296) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:42 CET LOG:  terminating any other active server processes
2009-11-30 13:39:42 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:42 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:41 CET
2009-11-30 13:39:42 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:42 CET LOG:  record with zero length at 0/11D4828
2009-11-30 13:39:42 CET LOG:  redo is not required
2009-11-30 13:39:42 CET LOG:  autovacuum launcher started
2009-11-30 13:39:42 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:42 CET LOG:  server process (PID 2304) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:42 CET LOG:  terminating any other active server processes
2009-11-30 13:39:42 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:42 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:42 CET
2009-11-30 13:39:42 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:42 CET LOG:  record with zero length at 0/11D486C
2009-11-30 13:39:42 CET LOG:  redo is not required
2009-11-30 13:39:43 CET LOG:  autovacuum launcher started
2009-11-30 13:39:43 CET LOG:  database system is ready to accept connections
2009-11-30 13:39:43 CET LOG:  server process (PID 2312) was terminated by signal 11: Segmentation fault
2009-11-30 13:39:43 CET LOG:  terminating any other active server processes
2009-11-30 13:39:43 CET LOG:  all server processes terminated; reinitializing
2009-11-30 13:39:43 CET LOG:  database system was interrupted; last known up at 2009-11-30 13:39:42 CET
2009-11-30 13:39:43 CET LOG:  database system was not properly shut down; automatic recovery in progress
2009-11-30 13:39:43 CET LOG:  record with zero length at 0/11D48B0
2009-11-30 13:39:43 CET LOG:  redo is not required
2009-11-30 13:39:43 CET LOG:  autovacuum launcher started
2009-11-30 13:39:43 CET LOG:  database system is ready to accept connections
                                                                         [fail]

So what happened and what can I do to solve this? Thanks for replies