Postmaster failing to start on reboot

surabhi.ahuja wrote:

Hello everyone,

I reboot my machine while postmaster is up.

after the m/c gets rebooted , I grep for the process "postmaster",
and it does not find it.

So, I try starting postmaster. and it displays the following error
message: HINT: If you're sure there are no old server processes
still running, remove the shared memory block with the command "ipcr
m", or just delete the file
"/export/home1/sdc_image_pool/dbx/postmaster.pid".

does it means that i will have to delete the postmaster.pid file ..in
such a scenarion always?

No, only when it doesn't close down properly. Check your system logs to
see what happened.

--
Richard Huxton
Archonet Ltd

Richard Huxton <dev@archonet.com> writes:

surabhi.ahuja wrote:

So, I try starting postmaster. and it displays the following error
message: HINT: If you're sure there are no old server processes
still running, remove the shared memory block with the command "ipcr
m", or just delete the file
"/export/home1/sdc_image_pool/dbx/postmaster.pid".

does it means that i will have to delete the postmaster.pid file ..in
such a scenarion always?

No, only when it doesn't close down properly. Check your system logs to
see what happened.

Also, what PG version is this exactly? More recent versions have better
defenses against being fooled by stale postmaster.pid files. It matters
what postmaster startup script you're using, too.

regards, tom lane

i am using PostgreSQL 8.0.0
and the statrtup script i am using is as follows:

*****
#! /bin/sh
# dbxd Script for starting up the PostgreSQL
# server in the daemon mode
#
#

# postgreSQL version is:
PGVERSION=8.0
# Name of the script
NAME=dbxd
# Command issued start/stop/restart
action="$1"
# Get SDC configiration
# . $SDCHOME/.SdCrc
# Set defaults for port and database directory
POSTGRES_LOG="$SDCHOME/nuevo/logfiles/postgreslog"
if [ "`uname`" = "Linux" ]; then
#DEVMACHINE=`file /export/dbsroot | grep -c directory`
POSTMASTER=/usr/bin/postmaster
PGCTL="/usr/bin/pg_ctl -w "
INITDB=/usr/bin/initdb
PGDATA=$SdC_IMAGE_POOL/dbx
PGPORT=5432
else
echo "Cannot launch POSTGRES , unknown OS"
echo " [ FAILED ]"
exit 1
fi
if [ "`uname`" = "Linux" ]; then
INITD=/etc/rc.d/init.d
. $INITD/functions
# Get config.
. /etc/sysconfig/network
fi
# Check that networking is up.
# Pretty much need it for postmaster.
if [ "`uname`" = "Linux" ]; then
[ "${NETWORKING}" = "no" ] && exit 0
fi
start(){
# Check for the PGDATA structure
if [ -f $PGDATA/PG_VERSION ] && [ -d $PGDATA/base ]
then
# Check version of existing PGDATA
INSTPG_VERSION=`cat $PGDATA/PG_VERSION`
if [ $INSTPG_VERSION != '8.0' -a $INSTPG_VERSION != '8.1' ]
then
echo "An old version of the database format was found.\n"
exit 1
fi
else
# No existing PGDATA - call initdb
echo "Initializing database: "
#chmod 755 /var/lib/pgsql
if [ ! -d $PGDATA ]
then
mkdir -p $PGDATA
fi
chown $SDCUSER:$SDCUSER $PGDATA
chmod go-rwx $PGDATA
# Make sure the locale from the initdb is preserved for later startups...
[ -f /etc/sysconfig/i18n ] && cp /etc/sysconfig/i18n $PGDATA/../initdb.i18n
# Just in case no locale was set, use en_US on Linux
if [ "`uname`" = "Linux" ]; then
[ ! -f /etc/sysconfig/i18n ] && echo "LANG=en_US" > $PGDATA/../initdb.i18n
fi
# Initialize the database
if [ "`uname`" = "Linux" ]; then
/bin/sh -c "$INITDB --pgdata=$PGDATA > /dev/null 2>&1" < /dev/null
fi
# Modify original postgres settings so that local connection are trusted
mv $PGDATA/pg_hba.conf $PGDATA/pg_hba.conf.orig
cat $PGDATA/pg_hba.conf.orig | sed "s/^local.*/local all all trust/" > $PGDATA/pg_hba.conf
chown $SDCUSER:$SDCUSER $PGDATA/pg_hba.conf
chmod 600 $PGDATA/pg_hba.conf
rm $PGDATA/pg_hba.conf.orig
#Copy the configuration file to the database - TBD
#cp /export/home/sdc/database_scripts/config/postgresql.conf $PGDATA/
#chown postgres:postgres $PGDATA/postgresql.conf
#chmod 600 $PGDATA/postgresql.conf
fi
# Check for postmaster already running...
# note that pg_ctl only looks at the data structures in PGDATA
# you really do need the pidof()
if [ "`uname`" = "Linux" ]; then
pid=`pidof -s postmaster`
else
pid=`ps -eaf | grep postmaster | grep -v grep | tail -1 | awk '{print $2}'`
fi
if [ $pid ] && $PGCTL status -D $PGDATA > /dev/null 2>&1
then
echo "Postmaster already running."
else
if [ "`uname`" = "Linux" ]; then
#su -l postgres -s /bin/sh -c "$PGCTL -l $POSTGRES_LOG -D $PGDATA -p $POSTMASTER -o '-p ${PGPORT}' start

/dev/null 2>&1" < /dev/null

rm -f /tmp/.s.PGSQL.${PGPORT} > /dev/null
rm -f /tmp/.s.PGSQL.${PGPORT}.lock > /dev/null
/bin/sh -c "$PGCTL -l $POSTGRES_LOG -D $PGDATA -p $POSTMASTER -o '-p ${PGPORT}' start > /dev/null 2>&1"
< /dev/null
fi
sleep 1
if [ "`uname`" = "Linux" ]; then
pid=`pidof -s postmaster`
else
pid=`ps -eaf | grep postmaster | grep -v grep | tail -1 | awk '{print $2}'`
fi
if [ $pid ]
then
#echo "success $PSQL_START"
echo_success
else
#echo "failure $PSQL_START"
echo_failure
fi
fi
}
stop(){
echo "Stopping ${NAME} service: "
if [ "`uname`" = "Linux" ]; then
#su -l postgres -s /bin/sh -c "$PGCTL stop -D $PGDATA -s -m fast" > /dev/null 2>&1
/bin/sh -c "$PGCTL stop -D $PGDATA -s -m fast" > /dev/null 2>&1
fi
ret=$?
if [ $ret -eq 0 ]
then
#echo "success"
echo_success
else
echo_failure
if [ "`uname`" = "Linux" ]; then
#su -l postgres -s /bin/sh -c "$PGCTL stop -D $PGDATA -s -m immediate" > /dev/null 2>&1
/bin/sh -c "$PGCTL stop -D $PGDATA -s -m immediate" > /dev/null 2>&1
fi
fi
echo
}
case $action in
start)
start
;;
stop)
stop
;;
*)
echo "Usage: $0 {start|stop|status|restart|condrestart|reload|force-reload}"
exit 1
esac
exit 0

*****

for starting postmaster i run dbxd start
and for shutting it down i run dbxd stop.

Can you please study it once and suggest if I have missed something.

Please see the highlighted section (in red) . do i also need to remove the pid file also . i mean with the other rm commands do i need to give rm -f $PGDATA /postmaster.pid also?

Thank You,
Regards
Surabhi

________________________________

From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Wed 11/9/2005 9:23 PM
To: Richard Huxton
Cc: surabhi.ahuja; pgsql-general@postgresql.org
Subject: Re: [GENERAL] Postmaster failing to start on reboot

***********************
Your mail has been scanned by InterScan VirusWall.
***********-***********

Richard Huxton <dev@archonet.com> writes:

surabhi.ahuja wrote:

So, I try starting postmaster. and it displays the following error
message: HINT: If you're sure there are no old server processes
still running, remove the shared memory block with the command "ipcr
m", or just delete the file
"/export/home1/sdc_image_pool/dbx/postmaster.pid".

does it means that i will have to delete the postmaster.pid file ..in
such a scenarion always?

No, only when it doesn't close down properly. Check your system logs to
see what happened.

Also, what PG version is this exactly? More recent versions have better
defenses against being fooled by stale postmaster.pid files. It matters
what postmaster startup script you're using, too.

regards, tom lane

The error

"If you're sure there are no old server processes

still running, remove the shared memory block with the command "ipcr
m", or just delete the file
"/export/home1/sdc_image_pool/dbx/postmaster.pid".

was looged in the Postgres Log file that i give at the time of starting postmaster.

how do i check my system logs to get further info?
I am sorry i am still in the learning phase .

thanks
Regards
Surabhi

________________________________

From: Richard Huxton [mailto:dev@archonet.com]
Sent: Wed 11/9/2005 8:23 PM
To: surabhi.ahuja
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Postmaster failing to start on reboot

***********************
Your mail has been scanned by InterScan VirusWall.
***********-***********

surabhi.ahuja wrote:

Hello everyone,

I reboot my machine while postmaster is up.

after the m/c gets rebooted , I grep for the process "postmaster",
and it does not find it.

So, I try starting postmaster. and it displays the following error
message: HINT: If you're sure there are no old server processes
still running, remove the shared memory block with the command "ipcr
m", or just delete the file
"/export/home1/sdc_image_pool/dbx/postmaster.pid".

does it means that i will have to delete the postmaster.pid file ..in
such a scenarion always?

No, only when it doesn't close down properly. Check your system logs to
see what happened.

--
Richard Huxton
Archonet Ltd

Another thing that has been noted is ...sometimes if i run the command

dbxd stop.
it fails to bring down postmaster. What should be done in such a situation?

right now we do a kill -9 postmaster

Thanks
regards
Surabhi ahuja

________________________________

From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Wed 11/9/2005 9:23 PM
To: Richard Huxton
Cc: surabhi.ahuja; pgsql-general@postgresql.org
Subject: Re: [GENERAL] Postmaster failing to start on reboot

***********************
Your mail has been scanned by InterScan VirusWall.
***********-***********

Richard Huxton <dev@archonet.com> writes:

surabhi.ahuja wrote:

So, I try starting postmaster. and it displays the following error
message: HINT: If you're sure there are no old server processes
still running, remove the shared memory block with the command "ipcr
m", or just delete the file
"/export/home1/sdc_image_pool/dbx/postmaster.pid".

does it means that i will have to delete the postmaster.pid file ..in
such a scenarion always?

No, only when it doesn't close down properly. Check your system logs to
see what happened.

Also, what PG version is this exactly? More recent versions have better
defenses against being fooled by stale postmaster.pid files. It matters
what postmaster startup script you're using, too.

regards, tom lane

surabhi.ahuja wrote:

i am using PostgreSQL 8.0.0

You should upgrade to 8.0.4 as soon as is convenient - there are 4 sets
of bugfixes available.

and the statrtup script i am using is as follows:

*****
#! /bin/sh
# dbxd Script for starting up the PostgreSQL
# server in the daemon mode
#
#

# postgreSQL version is:
PGVERSION=8.0
# Name of the script
NAME=dbxd
# Command issued start/stop/restart
action="$1"
# Get SDC configiration
# . $SDCHOME/.SdCrc

I don't recognise this script. Can I ask two questions:

Q1. What distribution of Linux are you running?
Q2. How did you install PostgreSQL?
Q3. Have you made any changes to this script?

In another email you mention that this script sometimes doesn't stop PG.
This is the relevant block of code, and you can see that the line
starting "su -l postgres" has been commented out and replaced.

That's strange, because my copy of pg_ctl refuses to run as root.

stop(){
echo "Stopping ${NAME} service: "
if [ "`uname`" = "Linux" ]; then
#su -l postgres -s /bin/sh -c "$PGCTL stop -D $PGDATA -s -m fast" > /dev/null 2>&1
/bin/sh -c "$PGCTL stop -D $PGDATA -s -m fast" > /dev/null 2>&1
fi
ret=$?
if [ $ret -eq 0 ]
then
#echo "success"
echo_success
else
echo_failure
if [ "`uname`" = "Linux" ]; then
#su -l postgres -s /bin/sh -c "$PGCTL stop -D $PGDATA -s -m immediate" > /dev/null 2>&1
/bin/sh -c "$PGCTL stop -D $PGDATA -s -m immediate" > /dev/null 2>&1
fi
fi
echo
}

Please see the highlighted section (in red) .

Most people will be viewing this in text-mode (including me). They won't
see the red. It appears to be deleting the unix socket and lock *AFTER*
starting up PG. I don't understand how that makes sense.

Q4. Where did you get this script?

do i also need to remove the pid file also .

What, after starting PG? How could that make sense?

i mean with the other rm commands do i need to give
rm -f $PGDATA /postmaster.pid also?

The standard script should start and stop PostgreSQL quite successfully.
If it isn't working the first place to look is your logs.
--
Richard Huxton
Archonet Ltd

Richard Huxton <dev@archonet.com> writes:

In another email you mention that this script sometimes doesn't stop PG.
This is the relevant block of code, and you can see that the line
starting "su -l postgres" has been commented out and replaced.
That's strange, because my copy of pg_ctl refuses to run as root.

We added the no-root check to pg_ctl in 8.0beta4, so AFAICS this script
should *never* work to stop the postmaster if you are indeed dealing
with an 8.0.0 release. The script change must have been made by someone
who was dealing with a pre-8.0 version (and even then, not one of the
later subreleases, because every branch since Oct 2004 has had this
check).

At least, it'd never work if executed by root. It might work if
executed by postgres --- dunno whether any of the other stuff is
root-only.

In any case, the short answer is to get rid of this script and get
one that works properly ...

regards, tom lane

hi,

in the script ithe statement to start and stop postmsater as the root is commented. thats how i saw the script( has been written by some one else)

will using 8.0.4 ensure proper starting and stopping of postmsater.

what abt the case in which the system is simply rebooted ...with postmsater already running)?

(attaching the script) again

thanks
regards
Surabhi