# 备份机制 > 备份脚本、调度、仓库和基础设施 --- 备份可以通过内置 [脚本](#script) 调用，使用节点 [crontab](#crontab) 调度， 由 [pgbackrest](https://pgbackrest.org/) 管理，并存储在备份仓库中， 仓库可以是本地磁盘文件系统或 MinIO / S3，具有不同的 [保留](#retention) 策略。 -------- ## 备份脚本 {#script} 您可以使用 [`pg_dbsu`](/zh/docs/pgsql/param#pg_dbsu) 用户（默认为 `postgres`）通过 `pgbackrest` 命令创建备份： ```bash tab="backup" pgbackrest --stanza=pg-meta --type=full backup # 为集群 pg-meta 创建全量备份 ``` ```bash tab="full" $ pgbackrest --stanza=pg-meta --type=full backup 2025-07-15 01:36:57.007 P00 INFO: backup command begin 2.54.2: --annotation=pg_cluster=pg-meta --compress-type=lz4 --delta --exec-id=88380-4b22e767 --expire-auto --log-level-console=info --log-level-file=info --log-path=/pg/log/pgbackrest --pg1-path=/pg/data --pg1-port=5432 --repo1-block --repo1-bundle --repo1-bundle-limit=20MiB --repo1-bundle-size=128MiB --repo1-cipher-pass= --repo1-cipher-type=aes-256-cbc --repo1-path=/pgbackrest --repo1-retention-full=14 --repo1-retention-full-type=time --repo1-s3-bucket=pgsql --repo1-s3-endpoint=sss.pigsty --repo1-s3-key= --repo1-s3-key-secret= --repo1-s3-region=us-east-1 --repo1-s3-uri-style=path --repo1-storage-ca-file=/etc/pki/ca.crt --repo1-storage-port=9000 --repo1-type=s3 --stanza=pg-meta --start-fast --type=full 2025-07-15 01:36:57.030 P00 INFO: execute non-exclusive backup start: backup begins after the requested immediate checkpoint completes 2025-07-15 01:36:57.105 P00 INFO: backup start archive = 000000010000000000000006, lsn = 0/6000028 2025-07-15 01:36:57.105 P00 INFO: check archive for prior segment 000000010000000000000005 2025-07-15 01:36:58.403 P00 INFO: execute non-exclusive backup stop and wait for all WAL segments to archive 2025-07-15 01:36:58.421 P00 INFO: backup stop archive = 000000010000000000000006, lsn = 0/6000120 2025-07-15 01:36:58.424 P00 INFO: check archive for segment(s) 000000010000000000000006:000000010000000000000006 2025-07-15 01:36:58.540 P00 INFO: new backup label = 20250715-013657F 2025-07-15 01:36:58.588 P00 INFO: full backup size = 44.5MB, file total = 1437 2025-07-15 01:36:58.589 P00 INFO: backup command end: completed successfully (1584ms) 2025-07-15 01:36:58.589 P00 INFO: expire command begin 2.54.2: --exec-id=88380-4b22e767 --log-level-console=info --log-level-file=info --log-path=/pg/log/pgbackrest --repo1-cipher-pass= --repo1-cipher-type=aes-256-cbc --repo1-path=/pgbackrest --repo1-retention-full=14 --repo1-retention-full-type=time --repo1-s3-bucket=pgsql --repo1-s3-endpoint=sss.pigsty --repo1-s3-key= --repo1-s3-key-secret= --repo1-s3-region=us-east-1 --repo1-s3-uri-style=path --repo1-storage-ca-file=/etc/pki/ca.crt --repo1-storage-port=9000 --repo1-type=s3 --stanza=pg-meta 2025-07-15 01:36:58.593 P00 INFO: repo1: time-based archive retention not met - archive logs will not be expired 2025-07-15 01:36:58.593 P00 INFO: expire command end: completed successfully (4ms) ``` ```bash tab="diff" $ pgbackrest --stanza=pg-meta --type=diff backup 2025-07-15 01:37:24.952 P00 INFO: backup command begin 2.54.2: --annotation=pg_cluster=pg-meta --compress-type=lz4 --delta --exec-id=88431-1b8ca3e0 --expire-auto --log-level-console=info --log-level-file=info --log-path=/pg/log/pgbackrest --pg1-path=/pg/data --pg1-port=5432 --repo1-block --repo1-bundle --repo1-bundle-limit=20MiB --repo1-bundle-size=128MiB --repo1-cipher-pass= --repo1-cipher-type=aes-256-cbc --repo1-path=/pgbackrest --repo1-retention-full=14 --repo1-retention-full-type=time --repo1-s3-bucket=pgsql --repo1-s3-endpoint=sss.pigsty --repo1-s3-key= --repo1-s3-key-secret= --repo1-s3-region=us-east-1 --repo1-s3-uri-style=path --repo1-storage-ca-file=/etc/pki/ca.crt --repo1-storage-port=9000 --repo1-type=s3 --stanza=pg-meta --start-fast --type=diff 2025-07-15 01:37:24.985 P00 INFO: last backup label = 20250715-013657F, version = 2.54.2 2025-07-15 01:37:24.985 P00 INFO: execute non-exclusive backup start: backup begins after the requested immediate checkpoint completes 2025-07-15 01:37:25.045 P00 INFO: backup start archive = 000000010000000000000008, lsn = 0/8000028 2025-07-15 01:37:25.045 P00 INFO: check archive for prior segment 000000010000000000000007 2025-07-15 01:37:26.204 P00 INFO: execute non-exclusive backup stop and wait for all WAL segments to archive 2025-07-15 01:37:26.220 P00 INFO: backup stop archive = 000000010000000000000008, lsn = 0/8000158 2025-07-15 01:37:26.223 P00 INFO: check archive for segment(s) 000000010000000000000008:000000010000000000000008 2025-07-15 01:37:26.337 P00 INFO: new backup label = 20250715-013657F_20250715-013724D 2025-07-15 01:37:26.381 P00 INFO: diff backup size = 424.3KB, file total = 1437 2025-07-15 01:37:26.381 P00 INFO: backup command end: completed successfully (1431ms) 2025-07-15 01:37:26.381 P00 INFO: expire command begin 2.54.2: --exec-id=88431-1b8ca3e0 --log-level-console=info --log-level-file=info --log-path=/pg/log/pgbackrest --repo1-cipher-pass= --repo1-cipher-type=aes-256-cbc --repo1-path=/pgbackrest --repo1-retention-full=14 --repo1-retention-full-type=time --repo1-s3-bucket=pgsql --repo1-s3-endpoint=sss.pigsty --repo1-s3-key= --repo1-s3-key-secret= --repo1-s3-region=us-east-1 --repo1-s3-uri-style=path --repo1-storage-ca-file=/etc/pki/ca.crt --repo1-storage-port=9000 --repo1-type=s3 --stanza=pg-meta 2025-07-15 01:37:26.386 P00 INFO: repo1: time-based archive retention not met - archive logs will not be expired 2025-07-15 01:37:26.386 P00 INFO: expire command end: completed successfully (5ms) ``` ```bash tab="incr" $ pgbackrest --stanza=pg-meta --type=incr backup 2025-07-15 01:37:30.305 P00 INFO: backup command begin 2.54.2: --annotation=pg_cluster=pg-meta --compress-type=lz4 --delta --exec-id=88449-eba235f7 --expire-auto --log-level-console=info --log-level-file=info --log-path=/pg/log/pgbackrest --pg1-path=/pg/data --pg1-port=5432 --repo1-block --repo1-bundle --repo1-bundle-limit=20MiB --repo1-bundle-size=128MiB --repo1-cipher-pass= --repo1-cipher-type=aes-256-cbc --repo1-path=/pgbackrest --repo1-retention-full=14 --repo1-retention-full-type=time --repo1-s3-bucket=pgsql --repo1-s3-endpoint=sss.pigsty --repo1-s3-key= --repo1-s3-key-secret= --repo1-s3-region=us-east-1 --repo1-s3-uri-style=path --repo1-storage-ca-file=/etc/pki/ca.crt --repo1-storage-port=9000 --repo1-type=s3 --stanza=pg-meta --start-fast --type=incr 2025-07-15 01:37:30.337 P00 INFO: last backup label = 20250715-013657F_20250715-013724D, version = 2.54.2 2025-07-15 01:37:30.337 P00 INFO: execute non-exclusive backup start: backup begins after the requested immediate checkpoint completes 2025-07-15 01:37:30.383 P00 INFO: backup start archive = 000000010000000000000009, lsn = 0/9000028 2025-07-15 01:37:30.383 P00 INFO: check archive for segment 000000010000000000000009 2025-07-15 01:37:31.191 P00 INFO: execute non-exclusive backup stop and wait for all WAL segments to archive 2025-07-15 01:37:31.230 P00 INFO: backup stop archive = 00000001000000000000000A, lsn = 0/A000050 2025-07-15 01:37:31.232 P00 INFO: check archive for segment(s) 000000010000000000000009:00000001000000000000000A 2025-07-15 01:37:31.356 P00 INFO: new backup label = 20250715-013657F_20250715-013730I 2025-07-15 01:37:31.403 P00 INFO: incr backup size = 8.3KB, file total = 1437 2025-07-15 01:37:31.403 P00 INFO: backup command end: completed successfully (1099ms) 2025-07-15 01:37:31.403 P00 INFO: expire command begin 2.54.2: --exec-id=88449-eba235f7 --log-level-console=info --log-level-file=info --log-path=/pg/log/pgbackrest --repo1-cipher-pass= --repo1-cipher-type=aes-256-cbc --repo1-path=/pgbackrest --repo1-retention-full=14 --repo1-retention-full-type=time --repo1-s3-bucket=pgsql --repo1-s3-endpoint=sss.pigsty --repo1-s3-key= --repo1-s3-key-secret= --repo1-s3-region=us-east-1 --repo1-s3-uri-style=path --repo1-storage-ca-file=/etc/pki/ca.crt --repo1-storage-port=9000 --repo1-type=s3 --stanza=pg-meta 2025-07-15 01:37:31.409 P00 INFO: repo1: time-based archive retention not met - archive logs will not be expired 2025-07-15 01:37:31.409 P00 INFO: expire command end: completed successfully (6ms) ``` ```bash tab="info" $ pgbackrest --stanza=pg-meta info stanza: pg-meta status: ok cipher: aes-256-cbc db (current) wal archive min/max (17): 000000010000000000000001/00000001000000000000000A full backup: 20250715-013441F timestamp start/stop: 2025-07-15 01:34:41+00 / 2025-07-15 01:34:43+00 wal start/stop: 000000010000000000000004 / 000000010000000000000004 database size: 43.9MB, database backup size: 43.9MB repo1: backup size: 8.3MB full backup: 20250715-013657F timestamp start/stop: 2025-07-15 01:36:57+00 / 2025-07-15 01:36:58+00 wal start/stop: 000000010000000000000006 / 000000010000000000000006 database size: 44.5MB, database backup size: 44.5MB repo1: backup size: 8.7MB diff backup: 20250715-013657F_20250715-013724D timestamp start/stop: 2025-07-15 01:37:24+00 / 2025-07-15 01:37:26+00 wal start/stop: 000000010000000000000008 / 000000010000000000000008 database size: 44.5MB, database backup size: 424.3KB repo1: backup size: 94KB backup reference total: 1 full incr backup: 20250715-013657F_20250715-013730I timestamp start/stop: 2025-07-15 01:37:30+00 / 2025-07-15 01:37:31+00 wal start/stop: 000000010000000000000009 / 00000001000000000000000A database size: 44.5MB, database backup size: 8.3KB repo1: backup size: 504B backup reference total: 1 full, 1 diff ``` 这里的 `stanza` 是数据库集群名称：[`pg_cluster`](/zh/docs/pgsql/param#pg_cluster)，对于默认设置是 `pg-meta`。 Pigsty 有一个别名 `pb` 和包装脚本 `pg-backup`，它们将当前集群名称填充为 stanza： ```bash {title="alias"} function pb() { local stanza=$(grep -o '\[[^][]*]' /etc/pgbackrest/pgbackrest.conf | head -n1 | sed 's/.*\[\([^]]*\)].*/\1/') pgbackrest --stanza=$stanza $@ } pb ... # pgbackrest --stanza=pg-meta ... pb info # pgbackrest --stanza=pg-meta info pb backup # pgbackrest --stanza=pg-meta backup ``` ```bash {title="script"} pg-backup full # 进行全量备份 = pgbackrest --stanza=pg-meta --type=full backup pg-backup incr # 进行增量备份 = pgbackrest --stanza=pg-meta --type=incr backup pg-backup diff # 进行差异备份 = pgbackrest --stanza=pg-meta --type=diff backup ``` -------- ## 定时调度 {#crontab} Pigsty 利用 Linux 的 crontab 来调度备份。您可以使用它定义您的备份策略。 例如，大多数单节点配置模板将为备份设置以下 [`node_crontab`](/zh/docs/node/param#node_crontab)。 ```yaml {title="每日凌晨1点全量备份"} node_crontab: [ '00 01 * * * postgres /pg/bin/pg-backup full' ] ``` 您可以使用 crontab 和 `pg-backup` 脚本设计更复杂的备份策略，例如： ```yaml {title="周一全量备份，工作日增量备份"} node_crontab: # 周一凌晨 1 点进行全量备份，工作日进行增量备份 - '00 01 * * 1 postgres /pg/bin/pg-backup full' - '00 01 * * 2,3,4,5,6,7 postgres /pg/bin/pg-backup' ``` 要应用 crontab 更改，使用 [`node.yml`](/zh/docs/node/playbook/#nodeyml) 在所有节点上更新 crontab。 ```bash {title="应用 crontab"} ./node.yml -t node_crontab -l pg-meta # 将 crontab 更改应用到 pg-meta 组 ``` -------- ## pgbackrest 以下是 Pigsty 对 pgbackrest 的设置详情： - pgbackrest 备份工具默认启用和配置（[`pgbackrest_enabled`](/zh/docs/pgsql/param/#pgbackrest_enabled)） - 在 [`pgsql.yml`](/zh/docs/pgsql/playbook/#pgsqlyml) 剧本的 `pg_install` 任务中安装，定义在 [`pg_packages`](/zh/docs/pgsql/param/#pg_packages) 中 - 在 [`pgsql.yml`](/zh/docs/pgsql/playbook/#pgsqlyml) 剧本的 `pg_backup` 任务中配置，[参数：PG_BACKUP](/zh/docs/pgsql/param/#pg_backup) - 在 `pgbackrest_init` 任务中初始化备份仓库，如果仓库存在则失败！（错误可以忽略） - 在 `pgbackrest_backup` 任务中创建初始备份，由 [`pgbackrest_init_backup`](/zh/docs/pgsql/param/#pgbackrest_init_backup) 控制 ### 文件系统层次结构 {#fhs} - 二进制文件：`/usr/bin/pgbackrest`，来自 PGDG 的 `pgbackrest` 包，在组别名 `pgsql-common` 中。 - 配置：`/etc/pgbackrest`，主配置是 [`/etc/pgbackrest/pgbackrest.conf`](https://github.com/pgsty/pigsty/blob/v3.7.0/roles/pgsql/templates/pgbackrest.conf)。 - 日志：`/pg/log/pgbackrest/*`，由 [`pgbackrest_log_dir`](/zh/docs/pgsql/param/#pgbackrest_log_dir) 控制 - 临时文件：`/pg/spool` 用作 pgbackrest 的临时缓冲目录 - 数据：如果选择默认的 `local` 文件系统备份仓库，则使用 `/pg/backup`。 此外，在 [PITR 恢复](/zh/docs/pgsql/backup/restore) 过程中， Pigsty 将创建一个临时的 `/pg/conf/pitr.conf` pgbackrest 配置文件。 并将 PostgreSQL 恢复日志写入 `/pg/tmp/recovery.log` 文件。 ### 监控 {#monitoring} 有一个 `pgbackrest_exporter` 服务运行在（[`pgbackrest_exporter_port`](/zh/docs/pgsql/param/#pgbackrest_exporter_port)：`9854`）上以导出 pgbackrest 指标。 您可以通过 [`pgbackrest_exporter_options`](/zh/docs/pgsql/param/#pgbackrest_exporter_options) 自定义它，并通过将 [`pgbackrest_exporter_enabled`](/zh/docs/pgsql/param/#pgbackrest_exporter_enabled) 设置为 `false` 来禁用它。 ### 初始备份 {#initial-backup} 当创建 PostgreSQL 集群时，Pigsty 会自动创建初始备份。 这是一个小备份，因为新集群几乎是空的。 它会留下一个标记文件 `/etc/pgbackrest/initial.done` 以避免再次创建初始备份。 如果您不想要它，请将 [`pgbackrest_init_backup`](/zh/docs/pgsql/param/#pgbackrest_initial) 设置为 `false`。 -------- ## 管理 {#administration} ### 启用备份 {#enable-backup} 如果您的数据库集群是在 [`pgbackrest_enable`](/zh/docs/pgsql/param/#pgbackrest_enable) 设置为 `true` 的情况下创建的，备份将自动启用。 如果是在 `false` 值下创建的，您可以使用以下命令启用 pgbackrest 组件： ```bash ./pgsql.yml -t pg_backup # 运行 pgbackrest 子任务 ``` ### 移除备份 {#remove-backup} Pigsty 在移除主实例（[`pg_role`](/zh/docs/pgsql/param/#pg_role) = `primary`）时会移除 pgbackrest 备份 stanza。 ```bash ./pgsql-rm.yml ./pgsql-rm.yml -e pg_rm_backup=false # 保持备份完整 ./pgsql-rm.yml -t pg_backup # 仅移除备份 ``` 使用 `pg_backup` 子任务仅移除备份，并使用 [`pg_rm_backup`](/zh/docs/pgsql/param/#pg_rm_backup) 参数保留备份。 如果您的备份仓库被**锁定**（例如，S3 / MinIO 有锁定选项），此操作将失败。 **备份移除** 移除备份可能导致永久数据丢失，这是一个危险操作，请极其谨慎地执行。 ### 列出备份 {#list-backup} 此命令将列出 pgbackrest 仓库中的所有备份（由所有集群共享） ```bash pgbackrest info ``` ### 手动备份 {#manual-backup} Pigsty 有一个内置脚本 `/pg/bin/pg-backup`，它封装了 `pgbackrest` 备份命令。 ```bash pg-backup # 进行增量备份 pg-backup full # 进行全量备份 pg-backup incr # 进行增量备份 pg-backup diff # 进行差异备份 ``` ### 基础备份 {#base-backup} Pigsty 有一个替代备份脚本 `/pg/bin/pg-basebackup`，它不依赖 `pgbackrest`，并为您提供数据库集群的物理副本。 默认备份目录是 `/pg/backup`。 ```bash tab="help" NAME pg-basebackup -- make base backup from PostgreSQL instance SYNOPSIS pg-basebackup -sdfeukr pg-basebackup --src postgres:/// --dst . --file backup.tar.lz4 DESCRIPTION -s, --src, --url Backup source URL, optional, "postgres:///" by default, if password is required, it should be given in url, ENV or .pgpass -d, --dst, --dir Where to put backup files, "/pg/backup" by default -f, --file Overwrite default backup filename, "backup_${tag}_${date}.tar.lz4" -r, --remove .lz4 Files mtime before n minutes ago will be removed, default is 1200 (20hour) -t, --tag Backup file tag, if not set, target cluster_name or local ip address will be used. Also used as part of DEFAULT filename -k, --key Encryption key when --encrypt is specified, default key is ${tag} -u, --upload Upload backup files to cloud storage, (need your own implementation) -e, --encryption Encrypt with RC4 using OpenSSL, if not key is specified, tag is used as key -h, --help Print this message ``` ```bash tab="backup" postgres@pg-meta-1:~$ pg-basebackup [2025-07-13 06:16:05][INFO] ================================================================ [2025-07-13 06:16:05][INFO] [INIT] pg-basebackup begin, checking parameters [2025-07-13 06:16:05][DEBUG] [INIT] #====== BINARY [2025-07-13 06:16:05][DEBUG] [INIT] pg_basebackup : /usr/pgsql/bin/pg_basebackup [2025-07-13 06:16:05][DEBUG] [INIT] openssl : /usr/bin/openssl [2025-07-13 06:16:05][DEBUG] [INIT] #====== PARAMETER [2025-07-13 06:16:05][DEBUG] [INIT] filename (-f) : backup_pg-meta_20250713.tar.lz4 [2025-07-13 06:16:05][DEBUG] [INIT] src (-s) : postgres:/// [2025-07-13 06:16:05][DEBUG] [INIT] dst (-d) : /pg/backup [2025-07-13 06:16:05][DEBUG] [INIT] tag (-t) : pg-meta [2025-07-13 06:16:05][DEBUG] [INIT] key (-k) : pg-meta [2025-07-13 06:16:05][DEBUG] [INIT] encrypt (-e) : false [2025-07-13 06:16:05][DEBUG] [INIT] upload (-u) : false [2025-07-13 06:16:05][DEBUG] [INIT] remove (-r) : -mmin +1200 [2025-07-13 06:16:05][INFO] [LOCK] acquire lock @ /tmp/backup.lock [2025-07-13 06:16:05][INFO] [LOCK] lock acquired success on /tmp/backup.lock, pid=107417 [2025-07-13 06:16:05][INFO] [BKUP] backup begin, from postgres:/// to /pg/backup/backup_pg-meta_20250713.tar.lz4 [2025-07-13 06:16:05][INFO] [BKUP] backup in normal mode pg_basebackup: initiating base backup, waiting for checkpoint to complete pg_basebackup: checkpoint completed pg_basebackup: write-ahead log start point: 0/7000028 on timeline 1 pg_basebackup: write-ahead log end point: 0/7000FD8 pg_basebackup: syncing data to disk ... pg_basebackup: base backup completed [2025-07-13 06:16:06][INFO] [BKUP] backup complete! [2025-07-13 06:16:06][INFO] [RMBK] remove local obsolete backup: 1200 [2025-07-13 06:16:06][INFO] [BKUP] find obsolete backups: find /pg/backup/ -maxdepth 1 -type f -mmin +1200 -name 'backup*.lz4' [2025-07-13 06:16:06][WARN] [BKUP] remove obsolete backups: [2025-07-13 06:16:06][INFO] [RMBK] remove old backup complete [2025-07-13 06:16:06][INFO] [LOCK] release lock @ /tmp/backup.lock [2025-07-13 06:16:06][INFO] [DONE] backup procedure complete! [2025-07-13 06:16:06][INFO] ================================================================ ``` 备份使用 `lz4` 压缩，您可以使用以下命令解压缩和提取 tarball： ```bash mkdir -p /tmp/data # 将备份提取到此目录 cat /pg/backup/backup_pg-meta_20250713.tar.lz4 | unlz4 -d -c | tar -xC /tmp/data ``` ### 逻辑备份 {#logical-backup} 您也可以使用 `pg_dump` 命令执行逻辑备份。 逻辑备份不能用于 PITR（时间点恢复）， 但它们对于在不同主版本之间迁移数据或实现灵活的数据导出逻辑很有用。 ### 从仓库引导 {#bootstrap-from-repo} 现在假设您有一个现有集群 `pg-meta`，并且想要**分叉**它作为 `pg-meta2`： 您需要创建新的 `pg-meta2` 集群分叉，然后在其上运行 `pitr`。