Running pgBackRest from a Dedicated Repository Host’¶
Description¶
pgBackRest runs on a dedicated backup server and stores repository on local or remote storage (NFS, S3, Azure or GCS compatible object stores).
Cron task active to take backups from the primary database cluster.
Manually reconfigure cron task to take backup from another server.
! Use case diagram
Create a Dedicated User on the Repository Host¶
The pgbackrest user is created to own the backups and archives
repository. Any user can own the repository, but it is recommended not
to use postgres or enterprisedb to avoid confusion.
$ sudo groupadd pgbackrest
$ sudo adduser -g pgbackrest -n pgbackrest
$ sudo chown pgbackrest: /var/log/pgbackrest
Setup Passwordless SSH Connection¶
pgBackRest requires a passwordless SSH connection to enable communication between the hosts.
The following example SSH commands should succeed without prompting you for a password:
# From the PostgreSQL nodes
$ sudo -u postgres ssh pgbackrest@backup-server
# From the EDB Postgres Advanced Server nodes
$ sudo -u enterprisedb ssh pgbackrest@backup-server
# From the repository host
$ sudo -u pgbackrest ssh postgres@postgres-node-1
$ sudo -u pgbackrest ssh postgres@postgres-node-2
$ ...
Configuration¶
Backup Server¶
The repository should be reachable from the backup server. It can be located on the various supported types described in the first use case .
For example, let us create /backup_space to store our backups and
archives locally:
$ sudo mkdir /backup_space
$ sudo chown pgbackrest: /backup_space
The [global] section of the configuration file will look like this:
[global]
repo1-path=/backup_space
repo1-retention-full=2
repo1-cipher-type=aes-256-cbc
repo1-cipher-pass=FIXME
process-max=FIXME
log-level-console=info
log-level-file=debug
start-fast=y
delta=y
Adjust the encryption passphrase and the maximum number of processes to use for compression usage and file transfer.
See the ‘Recommended Settings’ pages for more details.
The [demo] stanza section will contain specific pg- options for
each database node.
the primary database server configuration for PostgreSQL
pg1-host=postgres-node-1
pg1-path=/var/lib/pgsql/13/data
or for EDBPostgresAdvancedServer
pg1-host=postgres-node-1
pg1-host-user=enterprisedb
pg1-path=/var/lib/edb/as13/data
for every other PostgreSQL node
pg2-host=other_node_hostname_or_ip
pg2-path=/var/lib/pgsql/13/data
or for EDBPostgresAdvancedServer
pg2-host=other_node_hostname_or_ip
pg2-host-user=enterprisedb
pg2-path=/var/lib/edb/as13/data
Define multiple nodes using pg2 , pg3 ,… to reach standby
servers only when those servers are available.
Database server(s)¶
Update the pgBackRest configuration file on the database server(s):
# pgbackrest.conf
[global]
repo1-host=backup-server
repo1-host-user=pgbackrest
log-level-console=info
log-level-file=debug
delta=y
[demo]
pg1-path=/var/lib/pgsql/13/data
recovery-option=primary_conninfo=host=primary_vip user=replication_user ...
The ` demo page for more details.
Setup Archiving¶
Once pgBackRest is configured, set up the database archiver process on each node:
# postgresql.conf
archive_mode = on
archive_command = pgbackrest --stanza=demo archive-push %p
As changing the archive_mode parameter requires a service restart,
and changing the archive_command only requires a configuration
reload, we recommend enabling archive_mode with an empty
archive_command (or pointing to /bin/true) when initiating a new
database cluster.
From the backup server (also called repository host), initiate the pgBackRest repository with the system user we created earlier:
$ sudo -u pgbackrest pgbackrest --stanza=demo stanza-create
Check the configuration and the archiving process:
$ sudo -u pgbackrest pgbackrest --stanza=demo check
Backup and Restore¶
See the Quickstart Backups and Restore sections for more details about those two commands.
The backup command will be executed on the repository host (aka.
backup-server), while the restore command should be executed on
database nodes (aka. postgres-node-1,…).
