Howto Backup PostgreSQL Databases Server With pg_dump command

by on March 1, 2006 · 27 comments· LAST UPDATED April 27, 2008

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Generally, I like to work with MySQL but some time my work force me to work with PostgreSQL database server.

Recently I had received a request to backup PostgreSQL databases as one of our client want to format and reinstall RHEL server.

PostgreSQL is a one of the robust, open source database server. Like MySQL database server, it provides utilities for creating a backup.

Step # 1: Login as a pgsql user

Type the following command:
$ su - pgsql
Get list of database(s) to backup:
$ psql -l

Step # 2: Make a backup using pg_dump

Backup database using pg_dump command. pg_dump is a utility for backing up a PostgreSQL database. It dumps only one database at a time. General syntax:
pg_dump databasename > outputfile

Task: dump a payroll database

Type the following command
$ pg_dump payroll > payroll.dump.outTo restore a payroll database:
$ psql -d payroll -f payroll.dump.outOR$ createdb payroll
$ psql payroll
However, in real life you need to compress database:$ pg_dump payroll | gzip -c > payroll.dump.out.gzTo restore database use the following command:$ gunzip payroll.dump.out.gz
$ psql -d payroll -f payroll.dump.out
Here is a shell script for same task:

#!/bin/bash
DIR=/backup/psql
[ ! $DIR ] && mkdir -p $DIR || :
LIST=$(psql -l | awk '{ print $1}' | grep -vE '^-|^List|^Name|template[0|1]')
for d in $LIST
do
  pg_dump $d | gzip -c >  $DIR/$d.out.gz
done

Another option is use to pg_dumpall command. As a name suggest it dumps (backs up) each database, and preserves cluster-wide data such as users and groups. You can use it as follows:$ pg_dumpall > all.dbs.outOR$ pg_dumpall | gzip -c > all.dbs.out.gzTo restore backup use the following command:
$ psql -f all.dbs.out postgresReferences:

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{ 27 comments… read them below or add one }

1 Nilesh Jain November 3, 2006 at 8:29 am

sir,
i am not able to take the backup of postgresql database.in pg_dump commnad it provide me “access denied ”
thanks

Reply

2 Yogesh June 20, 2007 at 7:25 am

can you provide how to do offiline backup of the postgresql database.

Reply

3 Daniel April 3, 2008 at 12:37 pm

Man, please remember that if you use the gzip option with pg_dumpall you HAVE TO use the gunzip to restore the backup.

gunzip all.dbs.out.gz

and then

psql -f all.dbs.out postgres

Reply

4 Leopold Palomo June 4, 2008 at 7:37 pm

The script has a little bug. On,
LIST=$(psql -l | awk ‘{ print $1}’ | grep -vE ‘^-|^List|^Name|template[0|1]‘)

if you have a list with several databases, the last row is number. For example in my case:
(19 rows)
and after the script
(19

so I propose you generate the LIST with this:
LIST=$(psql -l | awk ‘{ print $1}’ | grep -vE ‘^-|^List|^Name|template[0|1]|^\(‘)

Otherwise, it’s a very nice article.

Thanks.

Reply

5 Stefan June 28, 2008 at 3:37 pm

Thanks Vivek for the great script.

Just a few notes:

In the 3rd line
[ ! $DIR ] && mkdir -p $DIR || :
there should be no space character after the exclamation mark!
[ !$DIR ] && mkdir -p $DIR || :
like this it works for me.

@Leopold, thanks for your comment, I had the same problem and your expression for LIST was the solution :)

Reply

6 Basavaraj September 20, 2008 at 12:27 pm

i have taken backup of DB from other machine. so i want the run those DB on my box.

what are the steps i need to follow to achive it.

please help me

Reply

7 subodh keskar April 5, 2009 at 6:07 am

Needed help,new person in software using POSTGRE SQL please guide me with commands that will help to take backup easily and similarly restore when needed.

Reply

8 Joe Sircy July 9, 2009 at 5:06 pm

Nice tip, thanks. I have a few notes to share.

You can also avoid the number of rows returned with the “-t” option to psql:

psql -lt

Also, to run the script as root from cron, I used su to run the backup as the postgres user. My complete script:

#!/bin/sh
DIR=/backup/pgsql
LIST=$(su - postgres -c "psql -lt" |awk '{ print $1}' |grep -vE '^-|^List|^Name|template[0|1]')
for d in $LIST
do
  su - postgres -c "/usr/bin/pg_dump $d | gzip -c > $DIR/$d.sql.gz"
done

Reply

9 Hamidreza Zarei July 26, 2009 at 7:08 am

Hi
I want take backup from Postgresql in Tehran (city in Iran) and store it in Sqlserver 2005 in Mashad (city in Iran). Is it possible? How can I do it?
Regards,
Hamidreza

Reply

10 Ben September 11, 2009 at 4:40 pm

Hi. I had a slightly different experience. My cron job runs under root, but wanted to run the psql code under postgres user. My script therefore had to be changed to (Note the PGPASSWORD being set AND removed at the end):

#!/bin/bash
export PGPASSWORD=XXXXX
DIR=/home/ben/backups/psql
[ !$DIR ] && mkdir -p $DIR || :
LIST=$(su postgres -c “psql -lt” |awk ‘{ print $1}’ |grep -vE ‘^-|^List|^Name|template[0|1]‘)
for d in $LIST
do
pg_dump -U postgres $d | gzip -c > $DIR/$d.out.gz
done
export PGPASSWORD=

Reply

11 Brahma Prakash Tiwari November 6, 2009 at 10:50 am

Hi Denial this script is great for me -Brahma Prakash

Reply

12 nihed January 20, 2010 at 10:09 am

Nice,
For my case, I add split to have many files and can store it in dumy filesystem
pg_dumpall -Upostgres | gzip -c | split --bytes=1000m

Regards

Reply

13 Tanel March 22, 2010 at 3:17 pm

I got errors like this:
-su: /tmp/pgsql/erpengdemo.sql.gz: Permission denied
and tish:
pg_dump: [archiver (db)] connection to database “:” failed: FATAL: database “:” does not exist

And work around was:

#!/bin/sh
DIR=/backup/pgsql
[ !$DIR ] && mkdir -p $DIR || :

chown postgres:postgres $DIR

LIST=$(su – postgres -c “psql -lt” |awk ‘{ print $1}’ |grep -vE ‘^-|:|^List|^Name|template[0|1]‘)

for d in $LIST
do
su – postgres -c “/usr/bin/pg_dump $d | gzip -c > $DIR/$d.sql.gz”
done

Reply

14 Tanel March 22, 2010 at 3:18 pm

I got errors like this:
-su: /tmp/pgsql/erpengdemo.sql.gz: Permission denied
and tish:
pg_dump: [archiver (db)] connection to database “:” failed: FATAL: database “:” does not exist

And work around was:

#!/bin/sh
DIR=/backup/pgsql
[ !$DIR ] && mkdir -p $DIR || :

chown postgres:postgres $DIR

LIST=$(su - postgres -c "psql -lt" |awk '{ print $1}' |grep -vE '^-|:|^List|^Name|template[0|1]')

for d in $LIST
do
su - postgres -c "/usr/bin/pg_dump $d | gzip -c > $DIR/$d.sql.gz"
done

Reply

15 Andrew Gudkov April 28, 2010 at 7:52 pm

My version of script. The differencies:
1. I am asking psql to output databases without header (-t)
2. Simplified awk call to get rid of colons

#!/bin/bash
DIR=/backup/psql
LIST=$(psql -l -t -U root | awk 'NF >=5 { print $1}')
for d in $LIST; do
  pg_dump $d | gzip -c >  $DIR/$d.out.gz
done

Reply

16 Andrew Gudkov April 28, 2010 at 9:32 pm

Even better version :)

#!/bin/bash
#
# Dayly PostgreSQL maintainance: vacuuming and backuping.
#
##
set -e
for DB in $(psql -l -t -U root | awk 'NF >=5 { print $1}' | grep -v template0); do
  echo "[`date`] Maintaing $DB"
  echo 'VACUUM' | psql -U root -d $DB
  DUMP="$DB.`date '+%Y%m%d'`.sql.gz"
  PREV="$DB.`date -d'1 day ago' '+%Y%m%d'`.sql.gz"
  pg_dump -U root $DB | gzip -c > $DUMP
  md5sum -b $DUMP > $DUMP.md5
  if [ -f $PREV.md5 ] && diff $PREV.md5 $DUMP.md5; then
    rm $DUMP $DUMP.md5
  fi
done

Reply

17 koco May 19, 2010 at 7:55 am

I’ve made some script good for cron… It also has impemented restore commands for created backups :) and expiration limit (rotating)

#!/bin/bash
#
# Little script for PGSQLdump all databases (seperate files)
#
# v20100519 -- initial version by Koco
#
############################################################
MYEXECNAME=backup_postgres_v8.4_dbs_script.bash
USER=postgres
PGSQLCMD="/postgres1/v8.4.0/bin/psql --port 5433"
PGSQLCMDlist="$PGSQLCMD -l -t"
PGSQLdumpCMD="/postgres1/v8.4.0/bin/pg_dump --port 5433 -C"
APPEND=`date "+%Y%m%d-%H%M"`
BASEDIR=/postgres1/BACKUPS
BKPDIR=$BASEDIR/bkpV8.4.$APPEND
RSTFILE=$BASEDIR/bkpV8.4.$APPEND/1_restore_commands.README
#How many days do you wanna keep backups
TRESHOLD=30
if [ -f /postgres1/.postvolume ]
then
 DATABASES=`su - $USER -c "$PGSQLCMDlist" |grep \| |awk '{ print $1}'| grep -vE '^-|^List|^Name|template[0|1]'`
 mkdir $BKPDIR
 for db in $DATABASES
 do
   su - $USER -c "$PGSQLdumpCMD $db" | bzip2 -c > $BKPDIR/$db.dump.bz2
   echo "#---restore $db" >> $RSTFILE
   echo "bzcat $BKPDIR/$db.dump.bz2 > $BASEDIR/RST.dump.sql" >> $RSTFILE
   echo "su - $USER -c \"$PGSQLCMD -d $db -f $BASEDIR/RST.dump.sql\" " >> $RSTFILE
   echo "rm $BASEDIR/RST.dump.sql" >> $RSTFILE
   echo "#" >> $RSTFILE
 done
fi
# And find those old ones... and delete them (use nwrecover if you need them back)
FILES=`find $BASEDIR -type d -name 'bkpV8.4.*' -mtime +$TRESHOLD`
for f in $FILES
do
  echo "$APPEND: Treshold reached. Removed $f backup." >> $BASEDIR/$MYEXECNAME.log
  rm -rf $f
done

Reply

18 Nika May 28, 2010 at 4:21 pm

Hi,
I’m having problems with script and commands. could you help me with it?

#!/bin/bash
DIR=”/var/lib/pgsql”
BASE=”coupons”
DATE=”date +%m%d”

pg_dump $BASE | gzip > $DATE.coupons.gz
exit

Reply

19 sreemon December 6, 2010 at 1:52 pm

Hello,

We were using the PostgreSQL for Bugzill, Now we lost the Password Doc, how can we take the backup of the database,
We have the root password

regards

Reply

20 Amza Marian July 24, 2011 at 9:07 pm

You can list dbs with:

psql -l -t | cut -d'|' -f1 |sed -e 's/ //g'|grep .

A great example can be found here: https://www.rtfm.ro/baze-de-date/postgresql/backup-automat-la-bazele-de-date-postgresql/

Reply

21 Jasmine December 29, 2011 at 7:35 am

where should i type that commands?

Reply

22 blackmennewstyle June 21, 2013 at 2:41 pm

In your terminal (shell)

Reply

23 yoshie2x July 31, 2012 at 3:47 am

Hi everyone,
I am new to freebsd, and I used postgresql for my database management.
There was this scenario that i accidentally delete this particular database
and the backup setting for our server is not one by one, meaning all databases.

My question is how can I restore that particular database using the backup file which is a compressed file which is composed of several database?
Is there a way to extract a particular database on that file?

Reply

24 Yogesh September 27, 2012 at 6:50 am

Thanks Vivek for ur great help :)

Reply

25 Pascal April 4, 2013 at 9:06 pm

Another version to get the list of databases:
psql -lqt | grep -vE ‘^ +(template[0-9]+|postgres)? *\|’ | cut -d’|’ -f1| sed -e ‘s/ //g’ -e ‘/^$/d’

As my `psql -lqt` output is:
abcdefghij | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
abc | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

Reply

26 what is the path of out file in pg_dump November 20, 2013 at 6:30 am

I taken dump using pg_dump > sample.sql
where the file is goin to save?

Reply

27 Marian Amza November 20, 2013 at 12:15 pm

In your current directory. When you type the command from directory “/home/michael”, the backup will be in this dir.

Reply

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