Postgres Pro Backup Enterprise : Документация: 3.1: 3.9. Настройка политики хранения : Компания Postgres Professional

3.9. Настройка политики хранения
Пред.	Наверх	Глава 3. Сценарии использования	Начало	След.

3.9. Настройка политики хранения #

3.9.1. Удаление ненужных копий
3.9.2. Закрепление резервных копий
3.9.3. Настройка политики хранения архива WAL

Используя pg_probackup3, вы можете реализовать политики хранения резервных копий, в соответствии с которыми могут удаляться лишние копии, очищаться ненужные сегменты WAL. Кроме того, можно закреплять определённые копии, чтобы они сохранялись независимо от политики, как описано ниже. Эти подходы можно комбинировать произвольным образом.

3.9.1. Удаление ненужных копий #

По умолчанию все резервные копии, которые создаёт pg_probackup3, сохраняются в предназначенном для них каталоге. Для экономии дискового пространства вы можете настроить политику сохранения копий, чтобы ненужные копии удалялись.

Чтобы настроить политику хранения, задайте одну или несколько следующих переменных в файле pg_probackup3.conf с помощью команды set-config:

--retention-redundancy=избыточность

Определяет количество полных резервных копий, которое должно сохраняться в каталоге копий.

--retention-window=окно

Определяет самый ранний момент времени, на который pg_probackup3 может выполнить восстановление. В этом параметре задаётся количество дней от текущего момента. Например, если retention-window=6, должна сохраниться минимум одна копия старее шести дней, вместе с соответствующими файлами WAL и всеми последующими копиями.

Если установлены параметры --retention-redundancy и --retention-window, при очистке каталога от ненужных копий принимаются во внимание оба заданных ими условия. Например, если задать параметры --retention-redundancy=2 и --retention-window=6, программа pg_probackup3 должна сохранить две полные резервные копии, а также все копии, необходимые для восстановления данных, за последние шесть дней:

pg_probackup3 set-config -B каталог_копий --instance=имя_экземпляра --retention-redundancy=2 --retention-window=6

Рекомендуется всегда хранить как минимум две последние полные родительские копии, чтобы избежать ошибок при создании инкрементальных резервных копий.

Чтобы очистить каталог копий в соответствии с политикой хранения, нужно запустить команду retention с флагами сохранения, как показано ниже.

Например, чтобы удалить все резервные копии, считающиеся ненужными согласно установленной политике хранения, нужно выполнить следующую команду с флагом --delete-expired:

pg_probackup3 retention -B каталог_копий --instance=имя_экземпляра --delete-expired

Если вы хотите также удалить файлы WAL, которые больше не требуются ни для каких копий, укажите дополнительно --delete-wal:

pg_probackup3 retention -B каталог_копий --instance=имя_экземпляра --delete-expired --delete-wal

Вы также можете установить или переопределить текущую политику хранения, добавив параметры --retention-redundancy и --retention-window непосредственно при выполнении команды retention:

pg_probackup3 retention -B каталог_копий --instance=имя_экземпляра --delete-expired --retention-window=6 --retention-redundancy=2

Так как для инкрементальных копий требуется наличие всех родительских полных копий и всех предыдущих инкрементальных копий, даже по истечении срока их хранения эти копии нельзя удалить, пока минимум одна инкрементальная копия в цепочке удовлетворяет политике хранения. Чтобы не хранить устаревшие копии, которые всё ещё нужны для восстановления нужной инкрементальной копии, вы можете объединить их с ней, воспользовавшись ключом --merge-expired команды retention.

Предположим, что вы заархивировали экземпляр узла в каталог_копий со значением параметра --retention-window, равным 6, и значением параметра --retention-redundancy, равным 2, и на 11 февраля 2025 г. у вас есть следующие копии:

BACKUP INSTANCE 'dev', version 3
===================================================================================================================================
Instance Version ID        End time                 Mode  WAL Mode TLI Duration Data  WAL Zalg Zratio Start LSN  Stop LSN   Status
===================================================================================================================================
dev      17      full-1    2024-10-18 21:02:28+0000 FULL  ARCHIVE  1            87MB  -   none 1.00   0/10000028 0/10000128 OK
dev      17      delta-1-1 2024-11-11 00:36:01+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/12000028 0/12000128 OK
dev      17      delta-1-2 2024-11-15 15:43:01+0000 DELTA ARCHIVE  1            22MB  -   none 1.00   0/14000028 0/14000128 OK
dev      17      full-2    2024-11-22 14:24:04+0000 FULL  ARCHIVE  1            98MB  -   none 1.00   0/17000028 0/17000128 OK
dev      17      delta-2-1 2024-11-23 18:10:55+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/19000028 0/19000128 OK
 ----------------------------------------------------------retention window-----------------------------------------------------------
dev      17      delta-2-2 2025-02-06 23:44:33+0000 DELTA ARCHIVE  1            33MB  -   none 1.00   0/1C000028 0/1C000128 OK
dev      17      full-3    2025-02-08 03:31:33+0000 FULL  ARCHIVE  1            120MB -   none 1.00   0/1F000028 0/1F000128 OK
dev      17      delta-3-1 2025-02-09 07:18:31+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/21000028 0/21000128 OK
dev      17      delta-3-2 2025-02-10 11:05:17+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/23000028 0/23000128 OK
dev      17      full-4    2025-02-11 15:00:38+0000 FULL  ARCHIVE  1   1s       123MB -   none 1.00   0/25000028 0/25000128 OK

При запуске команды retention с флагом --delete-expired резервные копии с идентификаторами full-1, delta-1-1 и delta-1-2 будут удалены как устаревшие по критериям окна хранения и избыточности (требуемый набор полных резервных копий уже сохранён). delta-1-1 и delta-1-2 также будут удалены, поскольку базовая полная копия потеряла актуальность.

При запуске команды retention с флагом --merge-expired резервные копии full-2 и delta-2-1 будут объединены с delta-2-2. Объединение произойдёт именно с delta-2-2, так как это первая актуальная разностная копия, которую можно объединить с неактуальной разностной копией delta-2-1 и неактуальной полной копией full-2.

pg_probackup3 retention -B каталог_копий --instance=узел --delete-expired --merge-expired
pg_probackup3 show -B каталог_копий

BACKUP INSTANCE 'dev', version 3
=================================================================================================================================================
Instance Version ID                      End time                 Mode  WAL Mode TLI Duration Data  WAL Zalg Zratio Start LSN  Stop LSN   Status
=================================================================================================================================================
dev      17      2025-02-11-11-14-18-254 2025-02-11 11:14:18+0000 FULL  ARCHIVE  1            108MB  -  none 1.00   0/17000028 0/19000128 OK
dev      17      full-3                  2025-02-08 03:31:33+0000 FULL  ARCHIVE  1            120MB -   none 1.00   0/1F000028 0/1F000128 OK
dev      17      delta-3-1               2025-02-09 07:18:31+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/21000028 0/21000128 OK
dev      17      delta-3-2               2025-02-10 11:05:17+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/23000028 0/23000128 OK
dev      17      full-4                  2025-02-11 15:00:38+0000 FULL  ARCHIVE  1   1s       123MB -   none 1.00   0/25000028 0/25000128 OK

Поле Duration (Время) для объединённой копии показывает время, которое заняла процедура объединения.

3.9.2. Закрепление резервных копий #

Если вам нужно хранить отдельные копии дольше, чем допускает установленная политика хранения, вы можете дополнительно закрепить их на определённое время. Например:

pg_probackup3 set-backup -B каталог_копий --instance=имя_экземпляра -i ид_резервной_копии --ttl=30d

Эта команда задаёт срок хранения заданной резервной копии 30 дней, начиная с момента, указанного в атрибуте recovery-time этой копии.

Вы также можете явно задать время истечения срока хранения копии, воспользовавшись ключом --expire-time. Например:

pg_probackup3 set-backup -B каталог_копий --instance=имя_экземпляра -i ид_резервной_копии --expire-time="2027-04-09 18:21:32+00"

Также можно воспользоваться ключами --ttl и --expire-time команды backup и сразу закрепить создаваемую копию:

pg_probackup3 backup -B каталог_копий --instance=имя_экземпляра -b FULL --ttl=30d
pg_probackup3 backup -B каталог_копий --instance=имя_экземпляра -b FULL --expire-time="2027-04-09 18:21:32+00"

Определить, закреплена ли копия, можно с помощью команды show:

pg_probackup show -B каталог_копий --instance=имя_экземпляра -i ид_резервной_копии

Если копия закреплена, у неё есть атрибут expire-time, содержащий время окончания срока её хранения:

...
recovery-time = '2024-04-09 18:21:32+00'
expire-time = '2027-04-09 18:21:32+00'
data-bytes = 22288792
...

Отменить закрепление копии можно, передав в параметре --ttl ноль:

pg_probackup3 set-backup -B каталог_копий --instance=имя_экземпляра -i ид_резервной_копии --ttl=0

Примечание

Для закреплённой инкрементальной копии неявным образом закрепляются все нужные ей родительские копии. Если вы позже снимите с неё закрепление, последние также автоматически перестанут быть закреплёнными.

3.9.3. Настройка политики хранения архива WAL #

Когда осуществляется непрерывное архивирование WAL, сегменты WAL могут занимать много места на диске. Даже если вы время от времени удаляете старые резервные копии, с флагом --delete-wal могут быть удалены только те сегменты WAL, которые не относятся ни к какой копии из остающихся в каталоге. Однако если возможность восстановления на момент времени нужна только для последних копий, можно настроить политику хранения архива WAL, чтобы ограничить глубину архива и сэкономить место на диске.

Предположим, что вы заархивировали экземпляр node в каталог_копий и настроили непрерывное архивирование WAL:

pg_probackup3 show -B каталог_копий --instance=узел

BACKUP INSTANCE 'dev', version 3
=================================================================================================================================================
Instance Version ID                      End time                 Mode  WAL Mode TLI Duration Data  WAL Zalg Zratio Start LSN  Stop LSN   Status 
=================================================================================================================================================
dev      17      2025-02-11-15-13-36-756 2025-02-11 15:13:37+0000 FULL  ARCHIVE  1   1s       38MB  -   none 1.00   0/17000028 0/19000128 OK     
dev      17      2025-02-11-14-51-12-937 2025-02-06 23:44:33+0000 DELTA ARCHIVE  1            33MB  -   none 1.00   0/1C000028 0/1C000128 OK     
dev      17      2025-02-11-14-51-33-367 2025-02-08 03:31:33+0000 FULL  ARCHIVE  1            120MB -   none 1.00   0/1F000028 0/1F000128 OK     
dev      17      2025-02-11-14-51-51-220 2025-02-09 07:18:31+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/21000028 0/21000128 OK
dev      17      2025-02-11-14-51-57-473 2025-02-10 11:05:17+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/23000028 0/23000128 OK
dev      17      2025-02-11-15-00-37-815 2025-02-11 15:00:38+0000 FULL  ARCHIVE  1   1s       123MB -   none 1.00   0/25000028 0/25000128 OK

Вы можете проверить состояние архива WAL, запустив команду show с ключом --archive:

pg_probackup3 show -B каталог_копий --instance=node --archive

BACKUP INSTANCE 'dev', version 3
======================================================================================================================
TLI Parent TLI Switchpoint Min Segno                Max Segno                N segments Size  Zratio N backups Status 
======================================================================================================================
1              0/0         000000010000000000000001 000000010000000000000025 37         592MB 1.41   6         OK

Для удаления всех старых файлов WAL, которые не нужны для восстановления никаких из оставшихся резервных копий, выполните следующую команду:

pg_probackup retention -B каталог_копий --instance=node --delete-wal

[2025-02-11 15:23:30.422696] [14218] [128670453549440] [info] command: ./pg_probackup3 retention -B /work/backup --instance dev --delete-wal 
[2025-02-11 15:23:30.422738] [14218] [128670453549440] [info] execute command: 'retention', instance 'dev'
[2025-02-11 15:23:30.426167] [14218] [128670453549440] [info] WAL file 000000010000000000000001 removed
[2025-02-11 15:23:30.428095] [14218] [128670453549440] [info] WAL file 000000010000000000000002 removed
[2025-02-11 15:23:30.429776] [14218] [128670453549440] [info] WAL file 000000010000000000000003 removed
[2025-02-11 15:23:30.431838] [14218] [128670453549440] [info] WAL file 000000010000000000000004 removed
[2025-02-11 15:23:30.434124] [14218] [128670453549440] [info] WAL file 000000010000000000000005 removed
[2025-02-11 15:23:30.434196] [14218] [128670453549440] [info] WAL file 000000010000000000000005.00000028.backup removed
[2025-02-11 15:23:30.435852] [14218] [128670453549440] [info] WAL file 000000010000000000000006 removed
[2025-02-11 15:23:30.437579] [14218] [128670453549440] [info] WAL file 000000010000000000000007 removed
[2025-02-11 15:23:30.441360] [14218] [128670453549440] [info] WAL file 000000010000000000000008 removed
[2025-02-11 15:23:30.441815] [14218] [128670453549440] [info] WAL file 000000010000000000000008.00000028.backup removed
[2025-02-11 15:23:30.444488] [14218] [128670453549440] [info] WAL file 000000010000000000000009 removed
[2025-02-11 15:23:30.446902] [14218] [128670453549440] [info] WAL file 00000001000000000000000A removed
[2025-02-11 15:23:30.446961] [14218] [128670453549440] [info] WAL file 00000001000000000000000A.00000028.backup removed
[2025-02-11 15:23:30.448960] [14218] [128670453549440] [info] WAL file 00000001000000000000000B removed
[2025-02-11 15:23:30.450991] [14218] [128670453549440] [info] WAL file 00000001000000000000000C removed
[2025-02-11 15:23:30.451069] [14218] [128670453549440] [info] WAL file 00000001000000000000000C.00000028.backup removed
[2025-02-11 15:23:30.453236] [14218] [128670453549440] [info] WAL file 00000001000000000000000D removed
[2025-02-11 15:23:30.455291] [14218] [128670453549440] [info] WAL file 00000001000000000000000E removed
[2025-02-11 15:23:30.455462] [14218] [128670453549440] [info] WAL file 00000001000000000000000E.00000028.backup removed
[2025-02-11 15:23:30.458088] [14218] [128670453549440] [info] WAL file 00000001000000000000000F removed
[2025-02-11 15:23:30.459755] [14218] [128670453549440] [info] WAL file 000000010000000000000010 removed
[2025-02-11 15:23:30.459794] [14218] [128670453549440] [info] WAL file 000000010000000000000010.00000028.backup removed
[2025-02-11 15:23:30.461135] [14218] [128670453549440] [info] WAL file 000000010000000000000011 removed
[2025-02-11 15:23:30.462603] [14218] [128670453549440] [info] WAL file 000000010000000000000012 removed
[2025-02-11 15:23:30.462637] [14218] [128670453549440] [info] WAL file 000000010000000000000012.00000028.backup removed
[2025-02-11 15:23:30.464003] [14218] [128670453549440] [info] WAL file 000000010000000000000013 removed
[2025-02-11 15:23:30.465522] [14218] [128670453549440] [info] WAL file 000000010000000000000014 removed
[2025-02-11 15:23:30.465555] [14218] [128670453549440] [info] WAL file 000000010000000000000014.00000028.backup removed
[2025-02-11 15:23:30.466910] [14218] [128670453549440] [info] WAL file 000000010000000000000015 removed
[2025-02-11 15:23:30.468572] [14218] [128670453549440] [info] WAL file 000000010000000000000016 removed
[2025-02-11 15:23:30.468600] [14218] [128670453549440] [info] 30 WAL files removed.

Вы можете проверить состояние архива WAL, запустив команду show с ключом --archive:

pg_probackup3 show -B каталог_копий --instance=node --archive

BACKUP INSTANCE 'dev', version 3
======================================================================================================================
TLI Parent TLI Switchpoint Min Segno                Max Segno                N segments Size  Zratio N backups Status 
======================================================================================================================
1              0/0         000000010000000000000017 000000010000000000000025 15         240MB 1.47   6         OK

Пред.	Наверх	След.
3.8. Проверка целостности данных	Начало	3.10. Другие примеры

3.9. Configuring Retention Policy
Prev	Up	Chapter 3. Use Cases	Home	Next

3.9. Configuring Retention Policy #

3.9.1. Removing Redundant Backups
3.9.2. Pinning Backups
3.9.3. Configuring WAL Archive Retention Policy

With pg_probackup3, you can configure retention policy to remove redundant backups, clean up unneeded WAL files, as well as pin specific backups to ensure they are kept for the specified time, as explained in the sections below. All these actions can be combined together in any way.

3.9.1. Removing Redundant Backups #

By default, all backup copies created with pg_probackup3 are stored in the specified backup catalog. To save disk space, you can configure retention policy to remove redundant backup copies.

To configure retention policy, set one or more of the following variables in the pg_probackup3.conf file via set-config:

--retention-redundancy=redundancy

Specifies the number of full backup copies to keep in the backup catalog.

--retention-window=window

Defines the earliest point in time for which pg_probackup3 can complete the recovery. This option is set in the number of days from the current moment. For example, if retention-window=6, pg_probackup3 must keep at least one backup copy that is older than six days, with all the corresponding WAL files, and all the backups that follow.

If both --retention-redundancy and --retention-window options are set, both these conditions have to be taken into account when purging the backup catalog. For example, if you set --retention-redundancy=2 and --retention-window=6, pg_probackup3 has to keep two full backup copies, as well as all the backups required to ensure recoverability for the last six days:

pg_probackup3 set-config -B backup_dir --instance=instance_name --retention-redundancy=2 --retention-window=6

It is recommended to always keep at least two last parent full backups to avoid errors when creating incremental backups.

To clean up the backup catalog in accordance with retention policy, you have to run the retention command with retention flags, as shown below.

For example, to remove all backup copies that no longer satisfy the defined retention policy, run the following command with the --delete-expired flag:

pg_probackup3 retention -B backup_dir --instance=instance_name --delete-expired

If you would like to also remove the WAL files that are no longer required for any of the backups, you should also specify the --delete-wal flag:

pg_probackup3 retention -B backup_dir --instance=instance_name --delete-expired --delete-wal

You can also set or override the current retention policy by specifying --retention-redundancy and --retention-window options directly when running the retention command:

pg_probackup3 retention -B backup_dir --instance=instance_name --delete-expired --retention-window=6 --retention-redundancy=2

Since incremental backups require that their parent full backup and all the preceding incremental backups are available, if any of such backups expire, they still cannot be removed while at least one incremental backup in this chain satisfies the retention policy. To avoid keeping expired backups that are still required to restore an active incremental one, you can merge them with this backup using the --merge-expired flag when running the retention command.

Suppose you have backed up the node instance in the backup_dir directory, with the --retention-window option set to 6 and --retention-redundancy option set to 2, and you have the following backups available on February 11, 2025:

BACKUP INSTANCE 'dev', version 3
===================================================================================================================================
Instance Version ID        End time                 Mode  WAL Mode TLI Duration Data  WAL Zalg Zratio Start LSN  Stop LSN   Status
===================================================================================================================================
dev      17      full-1    2024-10-18 21:02:28+0000 FULL  ARCHIVE  1            87MB  -   none 1.00   0/10000028 0/10000128 OK
dev      17      delta-1-1 2024-11-11 00:36:01+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/12000028 0/12000128 OK
dev      17      delta-1-2 2024-11-15 15:43:01+0000 DELTA ARCHIVE  1            22MB  -   none 1.00   0/14000028 0/14000128 OK
dev      17      full-2    2024-11-22 14:24:04+0000 FULL  ARCHIVE  1            98MB  -   none 1.00   0/17000028 0/17000128 OK
dev      17      delta-2-1 2024-11-23 18:10:55+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/19000028 0/19000128 OK
 ----------------------------------------------------------retention window-----------------------------------------------------------
dev      17      delta-2-2 2025-02-06 23:44:33+0000 DELTA ARCHIVE  1            33MB  -   none 1.00   0/1C000028 0/1C000128 OK
dev      17      full-3    2025-02-08 03:31:33+0000 FULL  ARCHIVE  1            120MB -   none 1.00   0/1F000028 0/1F000128 OK
dev      17      delta-3-1 2025-02-09 07:18:31+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/21000028 0/21000128 OK
dev      17      delta-3-2 2025-02-10 11:05:17+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/23000028 0/23000128 OK
dev      17      full-4    2025-02-11 15:00:38+0000 FULL  ARCHIVE  1   1s       123MB -   none 1.00   0/25000028 0/25000128 OK

If you run the retention command with the --delete-expired flag, the backups with IDs full-1, delta-1-1, and delta-1-2 will be removed as they are expired both according to the retention window and due to redundancy (the required set of full backups has already been retained). delta-1-1 and delta-1-2 will also be removed since the base full backup is expired.

Running the retention command with the --merge-expired flag will merge backups full-2 and delta-2-1 with delta-2-2. The merge will occur with delta-2-2 as it is the first non-expired delta backup, which can be merged with expired delta backups delta-2-1 and expired full backup full-2. The new full backup ID will take the value of the current timestamp.

pg_probackup3 retention -B backup_dir --instance=node --delete-expired --merge-expired
pg_probackup3 show -B backup_dir

BACKUP INSTANCE 'dev', version 3
=================================================================================================================================================
Instance Version ID                      End time                 Mode  WAL Mode TLI Duration Data  WAL Zalg Zratio Start LSN  Stop LSN   Status
=================================================================================================================================================
dev      17      2025-02-11-11-14-18-254 2025-02-11 11:14:18+0000 FULL  ARCHIVE  1            108MB  -  none 1.00   0/17000028 0/19000128 OK
dev      17      full-3                  2025-02-08 03:31:33+0000 FULL  ARCHIVE  1            120MB -   none 1.00   0/1F000028 0/1F000128 OK
dev      17      delta-3-1               2025-02-09 07:18:31+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/21000028 0/21000128 OK
dev      17      delta-3-2               2025-02-10 11:05:17+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/23000028 0/23000128 OK
dev      17      full-4                  2025-02-11 15:00:38+0000 FULL  ARCHIVE  1   1s       123MB -   none 1.00   0/25000028 0/25000128 OK

The Duration field for the merged backup displays the time required for the merge.

3.9.2. Pinning Backups #

If you need to keep certain backups longer than the established retention policy allows, you can pin them for arbitrary time. For example:

pg_probackup3 set-backup -B backup_dir --instance=instance_name -i backup_id --ttl=30d

This command sets the expiration time of the specified backup to 30 days starting from the time indicated in its recovery-time attribute.

You can also explicitly set the expiration time for a backup using the --expire-time option. For example:

pg_probackup3 set-backup -B backup_dir --instance=instance_name -i backup_id --expire-time="2027-04-09 18:21:32+00"

Alternatively, you can use the --ttl and --expire-time options with the backup command to pin the newly created backup:

pg_probackup3 backup -B backup_dir --instance=instance_name -b FULL --ttl=30d
pg_probackup3 backup -B backup_dir --instance=instance_name -b FULL --expire-time="2027-04-09 18:21:32+00"

To check if the backup is pinned, run the show command:

pg_probackup3 show -B backup_dir --instance=instance_name -i backup_id

If the backup is pinned, it has the expire-time attribute that displays its expiration time:

...
recovery-time = '2024-04-09 18:21:32+00'
expire-time = '2027-04-09 18:21:32+00'
data-bytes = 22288792
...

You can unpin the backup by setting the --ttl option to zero:

pg_probackup3 set-backup -B backup_dir --instance=instance_name -i backup_id --ttl=0

Note

A pinned incremental backup implicitly pins all its parent backups. If you unpin such a backup later, its implicitly pinned parents will also be automatically unpinned.

3.9.3. Configuring WAL Archive Retention Policy #

When continuous WAL archiving is enabled, archived WAL segments can take a lot of disk space. Even if you delete old backup copies from time to time, the --delete-wal flag can purge only those WAL segments that do not apply to any of the remaining backups in the backup catalog. However, if point-in-time recovery is critical only for the most recent backups, you can configure WAL archive retention policy to keep WAL archive of limited depth and win back some more disk space.

Suppose you have backed up the node instance in the backup_dir directory and configured continuous WAL archiving:

pg_probackup3 show -B backup_dir --instance=node

BACKUP INSTANCE 'dev', version 3
=================================================================================================================================================
Instance Version ID                      End time                 Mode  WAL Mode TLI Duration Data  WAL Zalg Zratio Start LSN  Stop LSN   Status 
=================================================================================================================================================
dev      17      2025-02-11-15-13-36-756 2025-02-11 15:13:37+0000 FULL  ARCHIVE  1   1s       38MB  -   none 1.00   0/17000028 0/19000128 OK     
dev      17      2025-02-11-14-51-12-937 2025-02-06 23:44:33+0000 DELTA ARCHIVE  1            33MB  -   none 1.00   0/1C000028 0/1C000128 OK     
dev      17      2025-02-11-14-51-33-367 2025-02-08 03:31:33+0000 FULL  ARCHIVE  1            120MB -   none 1.00   0/1F000028 0/1F000128 OK     
dev      17      2025-02-11-14-51-51-220 2025-02-09 07:18:31+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/21000028 0/21000128 OK
dev      17      2025-02-11-14-51-57-473 2025-02-10 11:05:17+0000 DELTA ARCHIVE  1            23MB  -   none 1.00   0/23000028 0/23000128 OK
dev      17      2025-02-11-15-00-37-815 2025-02-11 15:00:38+0000 FULL  ARCHIVE  1   1s       123MB -   none 1.00   0/25000028 0/25000128 OK

You can check the state of the WAL archive by running the show command with the --archive flag:

pg_probackup3 show -B backup_dir --instance=node --archive

BACKUP INSTANCE 'dev', version 3
======================================================================================================================
TLI Parent TLI Switchpoint Min Segno                Max Segno                N segments Size  Zratio N backups Status 
======================================================================================================================
1              0/0         000000010000000000000001 000000010000000000000025 37         592MB 1.41   6         OK

To purge all unused WAL files (that do not apply to any of the remaining backups in the backup catalog) run the following command:

pg_probackup3 retention -B backup_dir --instance=node --delete-wal

[2025-02-11 15:23:30.422696] [14218] [128670453549440] [info] command: ./pg_probackup3 retention -B /work/backup --instance dev --delete-wal 
[2025-02-11 15:23:30.422738] [14218] [128670453549440] [info] execute command: 'retention', instance 'dev'
[2025-02-11 15:23:30.426167] [14218] [128670453549440] [info] WAL file 000000010000000000000001 removed
[2025-02-11 15:23:30.428095] [14218] [128670453549440] [info] WAL file 000000010000000000000002 removed
[2025-02-11 15:23:30.429776] [14218] [128670453549440] [info] WAL file 000000010000000000000003 removed
[2025-02-11 15:23:30.431838] [14218] [128670453549440] [info] WAL file 000000010000000000000004 removed
[2025-02-11 15:23:30.434124] [14218] [128670453549440] [info] WAL file 000000010000000000000005 removed
[2025-02-11 15:23:30.434196] [14218] [128670453549440] [info] WAL file 000000010000000000000005.00000028.backup removed
[2025-02-11 15:23:30.435852] [14218] [128670453549440] [info] WAL file 000000010000000000000006 removed
[2025-02-11 15:23:30.437579] [14218] [128670453549440] [info] WAL file 000000010000000000000007 removed
[2025-02-11 15:23:30.441360] [14218] [128670453549440] [info] WAL file 000000010000000000000008 removed
[2025-02-11 15:23:30.441815] [14218] [128670453549440] [info] WAL file 000000010000000000000008.00000028.backup removed
[2025-02-11 15:23:30.444488] [14218] [128670453549440] [info] WAL file 000000010000000000000009 removed
[2025-02-11 15:23:30.446902] [14218] [128670453549440] [info] WAL file 00000001000000000000000A removed
[2025-02-11 15:23:30.446961] [14218] [128670453549440] [info] WAL file 00000001000000000000000A.00000028.backup removed
[2025-02-11 15:23:30.448960] [14218] [128670453549440] [info] WAL file 00000001000000000000000B removed
[2025-02-11 15:23:30.450991] [14218] [128670453549440] [info] WAL file 00000001000000000000000C removed
[2025-02-11 15:23:30.451069] [14218] [128670453549440] [info] WAL file 00000001000000000000000C.00000028.backup removed
[2025-02-11 15:23:30.453236] [14218] [128670453549440] [info] WAL file 00000001000000000000000D removed
[2025-02-11 15:23:30.455291] [14218] [128670453549440] [info] WAL file 00000001000000000000000E removed
[2025-02-11 15:23:30.455462] [14218] [128670453549440] [info] WAL file 00000001000000000000000E.00000028.backup removed
[2025-02-11 15:23:30.458088] [14218] [128670453549440] [info] WAL file 00000001000000000000000F removed
[2025-02-11 15:23:30.459755] [14218] [128670453549440] [info] WAL file 000000010000000000000010 removed
[2025-02-11 15:23:30.459794] [14218] [128670453549440] [info] WAL file 000000010000000000000010.00000028.backup removed
[2025-02-11 15:23:30.461135] [14218] [128670453549440] [info] WAL file 000000010000000000000011 removed
[2025-02-11 15:23:30.462603] [14218] [128670453549440] [info] WAL file 000000010000000000000012 removed
[2025-02-11 15:23:30.462637] [14218] [128670453549440] [info] WAL file 000000010000000000000012.00000028.backup removed
[2025-02-11 15:23:30.464003] [14218] [128670453549440] [info] WAL file 000000010000000000000013 removed
[2025-02-11 15:23:30.465522] [14218] [128670453549440] [info] WAL file 000000010000000000000014 removed
[2025-02-11 15:23:30.465555] [14218] [128670453549440] [info] WAL file 000000010000000000000014.00000028.backup removed
[2025-02-11 15:23:30.466910] [14218] [128670453549440] [info] WAL file 000000010000000000000015 removed
[2025-02-11 15:23:30.468572] [14218] [128670453549440] [info] WAL file 000000010000000000000016 removed
[2025-02-11 15:23:30.468600] [14218] [128670453549440] [info] 30 WAL files removed.

You can check the state of the WAL archive by running the show command with the --archive flag:

pg_probackup3 show -B backup_dir --instance=node --archive

BACKUP INSTANCE 'dev', version 3
======================================================================================================================
TLI Parent TLI Switchpoint Min Segno                Max Segno                N segments Size  Zratio N backups Status 
======================================================================================================================
1              0/0         000000010000000000000017 000000010000000000000025 15         240MB 1.47   6         OK

Prev	Up	Next
3.8. Checking Data Integrity	Home	3.10. More Examples