LOG:  database system was shut down at 2006-06-10 10:04:38 CEST
LOG:  checkpoint record is at 0/A38A34
LOG:  redo record is at 0/A38A34; undo record is at 0/0; shutdown TRUE
LOG:  next transaction ID: 544; next OID: 17230
LOG:  database system is ready
LOG:  checkpoints are occurring too frequently (21 seconds apart)
HINT:  Consider increasing the configuration parameter "checkpoint_segments".

..............................

LOG:  shutting down
LOG:  database system is shut down
LOG:  shmctl(983040, 0, 0) failed: Invalid argument
LOG:  database system was shut down at 2006-06-10 12:05:33 CEST
LOG:  checkpoint record is at 0/1C0AE3C
LOG:  redo record is at 0/1C0AE3C; undo record is at 0/0; shutdown TRUE
LOG:  next transaction ID: 21649; next OID: 130537
LOG:  database system is ready

..............................

LOG:  shutting down
LOG:  database system is shut down
LOG:  shmctl(0, 0, 0) failed: Invalid argument
LOG:  database system was shut down at 2006-06-10 18:45:21 CEST
LOG:  checkpoint record is at 0/6EF9E98
LOG:  redo record is at 0/6EF9E98; undo record is at 0/0; shutdown TRUE
LOG:  next transaction ID: 66486; next OID: 350753
LOG:  database system is ready

..............................

LOG:  shutting down
LOG:  database system is shut down
LOG:  shmctl(0, 0, 0) failed: Invalid argument
LOG:  database system was shut down at 2006-06-10 18:45:21 CEST
LOG:  checkpoint record is at 0/6EF9E98
LOG:  redo record is at 0/6EF9E98; undo record is at 0/0; shutdown TRUE
LOG:  next transaction ID: 66486; next OID: 350753
LOG:  database system is ready

..............................

LOG:  background writer process (PID 4313) was terminated by signal 6
LOG:  terminating any other active server processes
LOG:  all server processes terminated; reinitializing
LOG:  shmctl(98305, 0, 0) failed: Invalid argument
LOG:  database system shutdown was interrupted at 2006-09-02 01:53:17 CEST
LOG:  could not open file "/var/lib/postgresql/data/pg_xlog/00000001000000000000001A" (log file 0, segment 26): No such file or directory
LOG:  invalid primary checkpoint record
LOG:  could not open file "/var/lib/postgresql/data/pg_xlog/00000001000000000000001A" (log file 0, segment 26): No such file or directory
LOG:  invalid secondary checkpoint record
PANIC:  could not locate a valid checkpoint record

..............................

ERROR:  xlog flush request 0/1FB59F90 is not satisfied --- flushed only to 0/1A85DADC
CONTEXT:  writing block 21 of relation 1663/350753/712697
ERROR:  xlog flush request 0/1FB59F90 is not satisfied --- flushed only to 0/1A85DADC
CONTEXT:  writing block 21 of relation 1663/350753/712697
WARNING:  could not write block 21 of 1663/350753/712697
DETAIL:  Multiple failures --- write error may be permanent.
ERROR:  xlog flush request 0/1FB59F90 is not satisfied --- flushed only to 0/1A85DADC
CONTEXT:  writing block 21 of relation 1663/350753/712697
WARNING:  could not write block 21 of 1663/350753/712697
DETAIL:  Multiple failures --- write error may be permanent.
ERROR:  xlog flush request 0/1FB59F90 is not satisfied --- flushed only to 0/1A85DADC
CONTEXT:  writing block 21 of relation 1663/350753/712697
WARNING:  could not write block 21 of 1663/350753/712697
DETAIL:  Multiple failures --- write error may be permanent.
ERROR:  xlog flush request 0/1FB59F90 is not satisfied --- flushed only to 0/1A85DADC
CONTEXT:  writing block 21 of relation 1663/350753/712697
WARNING:  could not write block 21 of 1663/350753/712697

and much more of those....