We wrote an improved postgresql dump bash script for Postgresql version 9.1. This one will save each dump file with the name: database_name_DAYNAME.sql.bz2
In this way, we would only have 7 backups at any time, because each file will be overwritten after seven days. Since our backup system (TSM) saves 7 versions of each file, we would then have 49 versions at any time. That means we can go 49 days back in time to restore a certain dumpfile. In addition the script saves monthly a dump file with the name: database_name_MONTHNAME.sql.bz2.
You can also set a variable TEST to ‘yes’ to, then the script will only dump one specific filename: database_name_daily.sql.bz2. This can be useful on Test servers, where you might not be interested in a historical backup back in time.

Here it is:

#!/bin/bash

## This scripts dumps all the databases in a Postgres 9.1 server, localhost
## 2 dump files are made for each database. One with Inserts another without.

## TODO
# - implement a 'if system is Test' option to minimize number of dump files UNDER PROGRESS
# - use functions instead?
# - some kind of integration with Jenkins?
# - fix the 2 strange '|' that appears in the DATABASE list FIXED?
# - Add timer so we can optimize speed of the script execution time
# - enable use of the logfile LOGFILE. Could be nice to log what this script is/has been doing and when.
# - number of days to keep a dump file could be a parameter to this script
# - enable print of name of the script, where the script is run (hostname and directory). Makes it easy to find the script on a server
# - would be nice to add a incremental feature for this script. Then one can dump files several times a day, without worrying about space problems on the harddisk DIFFICULT?
## TODO END

# Timer
start_time=$(date +%s)

# Variables
LOGFILE="/var/lib/pgsql/9.1/data/pg_log/pgsql_dump.log"
BACKUP_DIR="/var/backup/postgresql_dumps"
BACKUP_DIR2="var/backup/postgresql_dumps" # Gosh..
HOSTNAME=`hostname`
MAILLIST="someone att somewhere" # should be edited
# Is this a test system? Set TESTSYSTEM to 'yes' in order to remove date and time information from dumpfile names (in order to minimize number of dumpfiles).
TESTSYSTEM="no"
TODAY=$(date|awk '{ print $1 }')
MONTH=$(date|awk '{ print $1 }')
MONTHNAME=`date +%b --date '0 month'`
DAYINMONTH=$(date|awk '{ print $3 }')
YEAR=$(date | awk '{ print $6 }')

# Only postgres can run this script
if [ `whoami` != "postgres" ]; then
echo "pgsql_dump tried to run, but user is not postgres!" >> $LOGFILE
echo "You are not postgres, can not run."
echo "Try: su -c ./pgsql_dump.sh postgres"
exit;
fi

# Check if there any backup files. If not, something is wrong!
if [ `find $BACKUP_DIR -type f -name '*.sql.bz2' -mtime -2 | wc -l` -eq 0 ]; then
echo "There are no pgsql dumps for the last 2 days at $HOSTNAME. Something is wrong!" | mail -s "[PGSQLDUMP ERROR] $HOSTNAME" $MAILLIST
fi

# logfile might be nice to have (or maybe Jenkins is the way to go?)
if [ ! -e $LOGFILE ]; then
touch $LOGFILE
fi

if [ $TESTSYSTEM == "yes" ];then
#DATABASES=`psql -q -c "\l" | sed -n 4,/\eof/p | grep -v rows | grep -v template0 | awk {'print $1}' | sed 's/^://g' | sed -e '/^$/d' | grep -v '|'`
# For testing purposes
DATABASES="database-1
database-2"
else
DATABASES=`psql -q -c "\l" | sed -n 4,/\eof/p | grep -v rows | grep -v template0 | awk {'print $1}' | sed 's/^://g' | sed -e '/^$/d' | grep -v '|'`
fi

for i in $DATABASES; do

## Create folders for each database if they don't exist
if [ ! -d "$BACKUP_DIR/$i/" ];then
mkdir $BACKUP_DIR/$i
fi
if [ ! -d "$BACKUP_DIR/$i/daily" ];then
mkdir $BACKUP_DIR/$i/daily
fi
if [ ! -d "$BACKUP_DIR/$i/monthly" ];then
mkdir $BACKUP_DIR/$i/monthly
fi

# On Test servers we don't want dump files with date and time information
if [ $TESTSYSTEM == "yes" ];then
DAILYFILENAME="daily_$i"
MONTHLYFILENAME="monthly_$i"
ALLDATABASESFILENAME="all-databases"
else
DAILYFILENAME="daily_$i_$TODAY"
MONTHLYFILENAME="monthly_$i_$MONTHNAME"
ALLDATABASESFILENAME="all-databases_$TODAY"
fi

# backup for each weekday (Mon, Tue, ...)
nice -n 10 /usr/pgsql-9.1/bin/pg_dump --column-inserts $i > $BACKUP_DIR/$i/daily/"$DAILYFILENAME".sql
nice -n 10 tar cjf $BACKUP_DIR/$i/daily/"$DAILYFILENAME".sql.bz2 -C / $BACKUP_DIR2/$i/daily/"$DAILYFILENAME".sql
rm -f $BACKUP_DIR/$i/daily/"$DAILYFILENAME".sql

# dump with copy statements
nice -n 10 /usr/pgsql-9.1/bin/pg_dump $i > $BACKUP_DIR/$i/daily/"$DAILYFILENAME"_copy.sql
nice -n 10 tar cjf $BACKUP_DIR/$i/daily/"$DAILYFILENAME"_copy.sql.bz2 -C / $BACKUP_DIR2/$i/daily/"$DAILYFILENAME"_copy.sql
rm -f $BACKUP_DIR/$i/daily/"$DAILYFILENAME"_copy.sql

# monthly backup (Jan, Feb...)
if [ $DAYINMONTH==10 ]; then
cp -f $BACKUP_DIR/$i/daily/"$DAILYFILENAME".sql.bz2 $BACKUP_DIR/$i/monthly/"$MONTHLYFILENAME".sql.bz2
cp -f $BACKUP_DIR/$i/daily/"$DAILYFILENAME"_copy.sql.bz2 $BACKUP_DIR/$i/monthly/"$MONTHLYFILENAME"_copy.sql.bz2
fi

# Year backup
# coming after a while

done

## Full backup
nice -n 10 /usr/pgsql-9.1/bin/pg_dumpall --column-inserts > $BACKUP_DIR/"$ALLDATABASESFILENAME".sql
nice -n 10 /usr/pgsql-9.1/bin/pg_dumpall > $BACKUP_DIR/"$ALLDATABASESFILENAME"_copy.sql
nice -n 10 tar cjf $BACKUP_DIR/"$ALLDATABASESFILENAME".sql.bz2 -C / var/backup/postgresql_dumps/"$ALLDATABASESFILENAME".sql
nice -n 10 tar cjf $BACKUP_DIR/"$ALLDATABASESFILENAME"_copy.sql.bz2 -C / var/backup/postgresql_dumps/"$ALLDATABASESFILENAME"_copy.sql
rm -f $BACKUP_DIR/"$ALLDATABASESFILENAME".sql
rm -f $BACKUP_DIR/"$ALLDATABASESFILENAME"_copy.sql

## Vacuuming (is it really necessary for PG 9.1? Don't think so...)
#nice -n 10 vacuumdb -a -f -z -q

finish_time=$(date +%s)
echo "Time duration for pg_dump script at $HOSTNAME: $((finish_time - start_time)) secs." | mail $MAILLIST