Difference between revisions of "Cedeus DB backups"

Revision as of 12:27, 5 December 2014

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How to set up Automated Backups

The Objective of this exercise is to have an automated backup process of user-profiles and user contributed data, that is copied to a portable medium at least once a week.

General Workflow to Create the Backups

The backups contain several steps. Usually they consist of:

1. create a script that contain commands to
   • create a database dump =or= tar/zip the files in a particular folder
   • copy this dump file or zip archive to another machine from where it can be easily copied to portable medium, i.e. tape
2. create a cron tab entry that runs the backup script(s) at some set intervall, e.g. each night at 1am

Below now some personal notes on how to set things up:

Notifications

To get notified about the backups via email, a/the shell script may send emails via "mailx" - i.e Nail. => see http://klenwell.com/press/2009/03/ubuntu-email-with-nail/

Btw. postfix may work as well

=> ToDo: Install mail program

Example: cron Job that makes a Dump of the GeoNode DB

• create a shell script that contains the pgdump instructions - see for example /home/ssteinig/pgdbbackup.sh on CedeusDB
• test if script or script execution actually works. A simple script for testing may perhaps be this (/home/ssteinig/touchy.sh)

#!/bin/bash 
touch /home/ssteinig/ftw.text

• create a cron-tab entry for user ssteinig with "crontab -e"

  then add entry such as "00 01 * * * sh /home/ssteinig/geonodegisdb93backup.sh" to run the dump script daily at 1am

  => when using the user "postgres" to do the db dump

  • check if postgres user has a password assigned already (use ALTER... to do so: http://wiki.geosteiniger.cl/mediawiki-1.22.7/index.php/Setting_up_geonode#Some_PostgreSQL_commands )
  • create a .pgpass file to provide the password: http://wiki.postgresql.org/wiki/Pgpass

    Note, the pgpass file should have chmod 0600. If it does not, then pg will ask for a password.

• check also if the cron is running: "sudo service cron status" otherwise start it...
• to see what the cron tab contains use "crontab -l"

Dump example script geonodegisdb93backup.sh

#!/bin/bash
logfile="/home/ssteinig/geonode_db_backups/pgsql.log"
backup_dir="/home/ssteinig/geonode_db_backups"
touch $logfile

echo "Starting backup of databases " >> $logfile
dateinfo=`date '+%Y-%m-%d %H:%M:%S'`
timeslot=`date '+%Y%m%d-%H%M'`
/usr/bin/vacuumdb -z -h localhost -U postgres geonodegisdb93  >/dev/null 2>&1
/usr/bin/pg_dump -U postgres -i -F c -b geonodegisdb93 -h 127.0.0.1 -f $backup_dir/geonodegisdb93-backup-$timeslot.backup
echo "Backup and Vacuum complete on $dateinfo for database: geonodegisdb93 " >> $logfile
echo "Done backup of databases " >> $logfile
# sstein: email notification not used at the moment
# tail -16 /home/ssteinig/geonode_db_backups/pgsql.log | mailx blabla@blub.cl

This example is based on the shell script posted here: http://stackoverflow.com/questions/854200/how-do-i-backup-my-postgresql-database-with-cron For a better Postgres dump script it may be worth to look here: https://wiki.postgresql.org/wiki/Automated_Backup_on_Linux

File transfer

To tranfers files I decided, for safety reasons, to create a new cedeus backup user on the receiving computer (20xxb...p).

A file transfer can be accomplished using scp or better rsync e.g.:

• "scp /home/ssteinig/ftw.txt user@example.com:/home/backup_user/dbbackups/"

  • However, a ssh key should be generated first so no password needs to be provided. A detailed dscription can be found on: http://troy.jdmz.net/rsync/index.html
  • in short do "ssh-keygen -t rsa -b 2048 -f /home/thisuser/cron/thishost-rsync-key". But do not provide a pass phrase when generating it, otherwise it will always asked for it when establishing a connection.
  • Then copy the key to the other servers users .ssh folder (using scp), and add it to the authorized_keys. (Note, the authorized_keys should be chmod 700).
  • Then we would use "scp -i /home/ssteinig/cron/thishost-rsync-key /home/ssteinig/ftw.txt user@example.com:/home/backup_user/dbbackups/"
  • note that it is probably necessary to initialize a server connection once (with whatever file), so the connection gets an ECDDSA key fingerprint.
• having my ssh keys setup, the code for syncing the cedeusdb directory with rsync would be
  • "...ToDo..."

Performed CEDEUS Observatory Backups

Dump of the GeoNode DB - on CedeusDB

• server: CedeusDB
• cron job running nightly at 1:00am
• using the script geonodegisdb93backup.sh
• copies the PG dump file to CedeusGeoNode into folder /home/cedeusdbbackupuser/geonodedbbackups/

  => ToDo: perhaps change this last step and copy it to cedeusgis1 for straight backup on a drive

dump of the GeoNode user db - on CedeusGeonode VM

blabla

tar/zip of the (uploaded) GeoNode file data and docs - on CedeusGeonode Vm

blabla

MySQL dump for Elgg miCiudad - on CedeusGeonode VM

blabla

tar/zip of the (uploaded) Elgg miCiudad files - on CedeusGeonode VM

blabla

MySQL dump for Mediawiki(s) - on CedeusGeonode VM

blabla