Having done backups for MySQL using rsnapshot before I recently had to do the same thing for PostgreSQL. Turns out PostgreSQL has similar tools to do this and it’s actually quite easy to set it up.
First, assuming rsnapshot will run under the root user you’ll need to create a .pgpass file at /root/.pgpass that will hold the credentials that are required for setting up a connection with your database. The expected format is host:port:database:user:password, so for example:
localhost:*:mydbname:myusername:mypassword
With that in place create a shell script that will use this file and run the pg_dump program. Put it some place you can remember, e.g. /usr/local/bin/postgresql-backup.sh:
#!/bin/bash export PGPASS=/root/.pgpass pg_dump -w -h localhost -U myusername mydbname > postgresql-dump.sql gzip postgresql-dump.sql
Again, just as with the using rsnapshot for daily MySQL backups article you need to configure rsnapshot.
Next is setting up /etc/rsnapshot.conf which is easy as well. At the end of this file you’ll find all the instructions of which directories to backup. Enter the next line. Do note that rsnapshot.conf uses a tab to separate values.
backup_script /usr/local/bin/postgresql-backup.sh postgresql/
To enable daily backups uncomment the next line:
#interval hourly 6 interval daily 7 #interval weekly 4 #interval monthly 3
To make rsnapshot run every day update /etc/cron.d/rsnapshot:
# 0 */4 * * * root /usr/bin/rsnapshot hourly 30 3 * * * root /usr/bin/rsnapshot daily # 0 3 * * 1 root /usr/bin/rsnapshot weekly # 30 2 1 * * root /usr/bin/rsnapshot monthly
Finally, try running rsnapshot. After it has run check your backup directory, which on Ubuntu 12.04 defaults to /.snapshots/. Be sure to mount /.snapshots/ on a separate drive. Because what use is it if your data drive contains your backup and decides to commit suicide?
$ sudo rsnapshot daily
Your PostgreSQL backup file should now be located at /.snapshots/daily.0/postgresql/postgresql-dump.sql. You can restore this file with the psql commandline utility.