Re: BUG #2419: could not reattach to shared memory

Andy Male wrote:

Hi Andy,

This is your problem:

> 2006-05-07 23:44:20 10.10.12.100(4018)PANIC:  42501: could not write to log
> file 0, segment 90 at offset 2998272, length 8192: Permission denied
> 2006-05-07 23:44:20 10.10.12.100(4018)CONTEXT:  writing block 75 of relation
> 1663/20632/100738
>     SQL statement "update tbl_query_ui_consumer_session_mapping set
> ui_consumer_session_data_action_type_id = 3, client_received = false where
> session_id =  $1  and client_session_id =  $2 "
>     PL/pgSQL function "fn_driver_session_updated" line 58 at SQL
> statement
> 2006-05-07 23:44:20 10.10.12.100(4018)LOCATION:  XLogWrite, xlog.c:1474
> 2006-05-07 23:44:20 10.10.12.100(4018)STATEMENT:  select * from
> fn_Driver_Session_Updated($1::int8,$2::bool)

The "Permission denied" message is a report Postgres is getting from the
operating system.  Notice it is marked as PANIC -- an unrecoverable
error.  What you should be investigating is why does the operating
system reject the writing of that file.  It clearly is a database file;
try looking at the files named $PGDATA/base/20632/100738 or possibly
$PGDATA/pg_tblspc/1663/20632/100738.  What permissions do those files
have?  Who owns them?  If it's not the user who runs the Postgres
processes, or they are not accesible to it, then something else in the
system changed that, which is what you need to figure out and disable.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support