Barman v23
When an instance is given the barman role in config.yml, TPA will
configure it as a Barman server to take backups
of any other instances that name it in their backup setting.
instances: - Name: one backup: two … - Name: two role: - barman …
Multiple postgres instances can have the same Barman server named as
their backup; equally, one postgres instance can have a list of
Barman servers named as its backup and backups will be taken to all
of the named servers.
The default Barman configuration will connect to PostgreSQL using pg_receivewal to take continuous backups of WAL, and will take a full backup of the instance using rsync over ssh twice weekly. Full backups and WAL are retained for long enough to enable recovery to any point in the last 4 weeks.
Barman configuration
On each barman server, a global configuration file will be created
as /etc/barman.conf; this contains default values for many barman
configuration variables. For each postgres server being backed up,
an additional Barman configuration file is created: to back up the
server one, the file will be /etc/barman.d/one.conf, and the backups
will be stored in /var/lib/barman/one. The file and directory names
are taken from the backed-up instance's backup_name setting, defaulting
to the instance's name.
The following variables can be set on the backed-up instance and are
passed through into Barman's configuration with the prefix barman_
removed:
| variable | default |
|---|---|
| barman_archiver | false |
| barman_log_file | /var/log/barman.log |
| barman_backup_method | rsync |
| barman_compression | pigz |
| barman_reuse_backup | link |
| barman_parallel_jobs | 1 |
| barman_backup_options | concurrent_backup |
| barman_immediate_checkpoint | false |
| barman_network_compression | false |
| barman_basebackup_retry_times | 3 |
| barman_basebackup_retry_sleep | 30 |
| barman_minimum_redundancy | 3 |
| barman_retention_policy | RECOVERY WINDOW OF 4 WEEKS |
| barman_last_backup_maximum_age | 1 WEEK |
| barman_pre_archive_retry_script | |
| barman_post_backup_retry_script | |
| barman_post_backup_script | |
| barman_streaming_wals_directory |
Backup scheduling
TPA installs a cron job in /etc/cron.d/barman which will run every
minute and invoke barman cron to perform maintenance tasks.
For each instance being backed up, it installs another cron job in
/etc/cron.d/<backup_name> which takes the backups of that instance.
This job runs as determined by the barman_backup_interval variable for
the instance, with the default being to take backups at 04:00 every
Wednesday and Saturday.
SSH keys
TPA will generate ssh key pairs for the postgres and barman
users and install them into the respective ~/.ssh directories, and add
them to each other's authorized_keys file. The postgres user must be
able to ssh to the barman server in order to archive WAL segments (if
configured), and the barman user must be able to ssh to the Postgres
instance to take or restore backups.
- On this page
- Barman configuration
- Backup scheduling
- SSH keys