could not write to log -> PANIC -> System down

Hello friends,

we have some strange problem, postmaster (pg 8.1 /win32)
suddenly shutdown because of "no reason".

The interesting thing is that this occurs always at
almost same time (between 0.00 and 0.30h), in that time period is
running system backup (Veristas backupexec agent) - starts at 23:30.
The problem occurs randomly.
In two of cases we have UPDATE/INSERT operation, but in third case - no.

P.S. Why "autovacuum" runs every minute almost? Is this related?

Thanks in advanced!


================ LOG (2006-12-14) ==================
2006-12-14 00:00:51 LOG:  autovacuum: processing database "mtdb"

2006-12-14 00:01:52 LOG:  autovacuum: processing database "mtdb"

2006-12-14 00:02:53 LOG:  autovacuum: processing database "mtdb"

2006-12-14 00:03:54 LOG:  autovacuum: processing database "mtdb"

2006-12-14 00:04:56 LOG:  autovacuum: processing database "mtdb"

2006-12-14 00:06:02 LOG:  autovacuum: processing database "mtdb"

2006-12-14 00:06:02 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:02 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:03 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:03 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:03 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:03 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:04 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:04 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:04 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:04 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:06 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:06 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:06 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:06 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:06 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:06 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:06 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:06 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:07 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:07 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:07 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:07 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:08 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:08 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:08 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:08 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:09 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:09 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:09 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:09 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:10 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:10 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:10 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:10 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:10 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:10 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:10 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:10 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:11 ERROR:  could not write block 14725 of relation
1663/16388/61387: Permission denied

2006-12-14 00:06:11 CONTEXT:  writing block 14725 of relation
1663/16388/61387

2006-12-14 00:06:11 WARNING:  could not write block 14725 of
1663/16388/61387

2006-12-14 00:06:11 DETAIL:  Multiple failures --- write error may be
permanent.

2006-12-14 00:06:23 ERROR:  could not open relation 1663/16388/61399:
Invalid argument

2006-12-14 00:06:39 PANIC:  could not write to log file 4, segment 158 at
offset 15286272, length 32768: Permission denied

2006-12-14 00:06:39 STATEMENT:  INSERT INTO docs_pages_stats(doc_id,
lang_id, page, text_mode, rip, cookie)

                VALUES(2066, 1, 1, 'f', '87.118.162.34',
'a2446edc627fd6f2572b68af83d1b6d4')



This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

2006-12-14 00:06:39 LOG:  server process (PID 9912) was terminated by signal
3

2006-12-14 00:06:39 LOG:  terminating any other active server processes

2006-12-14 00:06:39 LOG:  all server processes terminated; reinitializing

2006-12-14 00:06:39 LOG:  database system was interrupted at 2006-12-14
00:06:12 FLE Standard Time

2006-12-14 00:06:39 LOG:  could not read from log file 4, segment 158 at
offset 15237120: Permission denied

2006-12-14 00:06:39 LOG:  invalid primary checkpoint record

2006-12-14 00:06:39 LOG:  could not read from log file 4, segment 158 at
offset 14417920: Permission denied

2006-12-14 00:06:39 LOG:  invalid secondary checkpoint record

2006-12-14 00:06:39 PANIC:  could not locate a valid checkpoint record



This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

2006-12-14 00:06:39 LOG:  startup process (PID 1092) was terminated by
signal 3

2006-12-14 00:06:39 LOG:  aborting startup due to startup process failure

2006-12-14 00:06:40 LOG:  logger shutting down


================ LOG (2006-12-13) ==================

2006-12-13 00:24:34 LOG:  autovacuum: processing database "mtdb"

2006-12-13 00:24:46 ERROR:  could not read block 14667 of relation
1663/16388/61387: Permission denied

2006-12-13 00:24:56 ERROR:  could not read block 14667 of relation
1663/16388/61387: Permission denied

2006-12-13 00:24:58 ERROR:  could not read block 14667 of relation
1663/16388/61387: Permission denied

2006-12-13 00:25:01 ERROR:  could not read block 14667 of relation
1663/16388/61387: Permission denied

2006-12-13 00:25:07 ERROR:  could not read block 14667 of relation
1663/16388/61387: Permission denied

2006-12-13 00:25:23 ERROR:  could not open relation 1663/16388/61399:
Invalid argument

2006-12-13 00:25:32 ERROR:  could not read block 0 of relation
1663/16388/61414: Permission denied

2006-12-13 00:25:35 LOG:  autovacuum: processing database "mtdb"

2006-12-13 00:25:36 ERROR:  could not read block 0 of relation
1663/16388/61414: Permission denied

2006-12-13 00:25:49 PANIC:  could not write to log file 4, segment 153 at
offset 7487488, length 8192: Permission denied

2006-12-13 00:25:49 STATEMENT:  UPDATE docs SET hits = hits + 1 WHERE
id=1449



This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

2006-12-13 00:25:49 LOG:  server process (PID 6200) was terminated by signal
3

2006-12-13 00:25:49 LOG:  terminating any other active server processes

2006-12-13 00:25:49 LOG:  all server processes terminated; reinitializing

2006-12-13 00:25:49 LOG:  database system was interrupted at 2006-12-13
00:23:00 FLE Standard Time

2006-12-13 00:25:49 LOG:  could not read from log file 4, segment 153 at
offset 7258112: Permission denied

2006-12-13 00:25:49 LOG:  invalid primary checkpoint record

2006-12-13 00:25:49 LOG:  could not read from log file 4, segment 153 at
offset 7020544: Permission denied

2006-12-13 00:25:49 LOG:  invalid secondary checkpoint record

2006-12-13 00:25:49 PANIC:  could not locate a valid checkpoint record



This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

2006-12-13 00:25:49 LOG:  startup process (PID 9652) was terminated by
signal 3

2006-12-13 00:25:49 LOG:  aborting startup due to startup process failure

2006-12-13 00:25:50 LOG:  logger shutting down


================ LOG (2006-12-05) ==================
2006-12-05 00:05:17 LOG:  autovacuum: processing database "mtdb"

2006-12-05 00:05:42 ERROR:  value too long for type character varying(255)

2006-12-05 00:05:53 ERROR:  value too long for type character varying(255)

2006-12-05 00:06:18 LOG:  autovacuum: processing database "mtdb"

2006-12-05 00:06:55 ERROR:  could not read block 985 of relation
1663/16388/16605: Permission denied

2006-12-05 00:06:55 ERROR:  could not read block 113 of relation
1663/16388/16605: Permission denied

2006-12-05 00:06:55 ERROR:  could not read block 4 of relation
1663/16388/16605: Permission denied

2006-12-05 00:07:18 LOG:  autovacuum: processing database "mtdb"

2006-12-05 00:07:22 ERROR:  could not read block 14023 of relation
1663/16388/61387: Permission denied

2006-12-05 00:07:39 ERROR:  could not read block 0 of relation
1663/16388/61407: Invalid argument

2006-12-05 00:07:53 PANIC:  could not write to log file 4, segment 93 at
offset 13664256, length 8192: Permission denied

2006-12-05 00:07:53 CONTEXT:  writing block 8851 of relation
1663/16388/61399



This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

2006-12-05 00:07:53 LOG:  background writer process (PID 8748) was
terminated by signal 3

2006-12-05 00:07:53 LOG:  terminating any other active server processes

2006-12-05 00:07:53 WARNING:  terminating connection because of crash of
another server process

2006-12-05 00:07:53 DETAIL:  The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.

2006-12-05 00:07:53 HINT:  In a moment you should be able to reconnect to
the database and repeat your command.

2006-12-05 00:07:53 WARNING:  terminating connection because of crash of
another server process

2006-12-05 00:07:53 DETAIL:  The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.

2006-12-05 00:07:53 HINT:  In a moment you should be able to reconnect to
the database and repeat your command.

2006-12-05 00:07:53 WARNING:  terminating connection because of crash of
another server process

2006-12-05 00:07:53 DETAIL:  The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.

2006-12-05 00:07:53 HINT:  In a moment you should be able to reconnect to
the database and repeat your command.

2006-12-05 00:07:53 WARNING:  terminating connection because of crash of
another server process

2006-12-05 00:07:53 DETAIL:  The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.

2006-12-05 00:07:53 HINT:  In a moment you should be able to reconnect to
the database and repeat your command.

2006-12-05 00:07:53 LOG:  all server processes terminated; reinitializing

2006-12-05 00:07:54 LOG:  database system was interrupted at 2006-12-05
00:03:10 FLE Standard Time

2006-12-05 00:07:54 LOG:  could not read from log file 4, segment 93 at
offset 13574144: Permission denied

2006-12-05 00:07:54 LOG:  invalid primary checkpoint record

2006-12-05 00:07:54 LOG:  could not read from log file 4, segment 93 at
offset 13369344: Permission denied

2006-12-05 00:07:54 LOG:  invalid secondary checkpoint record

2006-12-05 00:07:54 PANIC:  could not locate a valid checkpoint record



This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

2006-12-05 00:07:54 LOG:  startup process (PID 10032) was terminated by
signal 3

2006-12-05 00:07:54 LOG:  aborting startup due to startup process failure

2006-12-05 00:07:54 LOG:  logger shutting down