我是Postgresql的新手，我找到了一个名为Barman的工具，用于对数据库进行增量备份。但是这几个教程并没有多大帮助，因为它们不适合天真的用户。
有人可以帮助解释这些步骤，简单地如何使用Barman备份数据吗？那将是一个很大的帮助！我在 Ubuntu 18.04 中使用 Postgres 10.4。
我后来发现了这个很棒的教程，逐步解释了过程。这是迄今为止最有帮助的一个。我包含内容，以防页面更改时链接无效。
Barman(备份和恢复管理器)是用Python编写的PostgreSQL服务器灾难恢复的管理工具。Barman 可以在业务关键型环境中执行多台服务器的远程备份，并在恢复阶段帮助 DBA。 Barman 最需要的功能包括：备份目录、增量备份、保留策略、远程恢复、WAL 文件和备份的存档和压缩。
设置pgbarman的步骤：
第 1 步：安装 PostgreSQL-9.4 或 9.5。
从下面的链接下载PostgreSQL
https://ftp.postgresql.org/pub/source/v9.5.1/postgresql-9.5.1.tar.bz2
第 2 步：从下面的链接下载 pgbarman。
https://sourceforge.net/projects/pgbarman/files/1.5.1/barman-1.5.1.tar.gz/download
步骤3：安装pgbarman之前安装先决条件 以下是必要的先决条件。
蟒蛇 2.6 或 2.7 蟒蛇模块：
- 参数完成
- >= 0.21.2
- 心理科普2
- python-dateutil <2.0(因为2.0版本需要python3)
- 分发(可选)
PostgreSQL>= 8.3 rsync>= 3.0.4
步骤4：解压缩pgbarman文件并安装它，如下所示
[root@localhost ~] tar -xvf barman-1.5.1.tar.gz
[root@localhost ~] cd barman-1.5.1
[root@localhost barman-1.5.1] python2.6 setup.py build
[root@localhost barman-1.5.1] python2.6 setup.py install
第 5 步：将 barman.conf 从 doc 复制到/etc/
[root@localhost barman-1.5.1] cp doc/barman.conf /etc/
第 6 步：创建用户 barman 并更改/etc/barman.conf 的所有者
[root@localhost barman-1.5.1]# chown -R barman:barman /etc/barman.conf
步骤7：在barman服务器和postgres服务器之间进行无密码身份验证。
[barman@localhost ~]$ ssh-keygen
[barman@localhost ~]$ ssh-copy-id -i .ssh/id_rsa.pub postgres@127.0.0.1
对 postgres 用户重复上述步骤。
[root@localhost barman-1.5.1]# su - postgres
[postgres@localhost ~]$ ssh-keygen
[postgres@localhost ~]$ ssh-copy-id -i .ssh/id_rsa.pub barman@127.0.0.1
步骤8：编辑barman.conf并在配置文件中编辑以下参数
[barman]
barman_home = /home/barman
barman_user = barman
log_file = /home/barman/barman.log
compression = gzip
reuse_backup = link
minimum_redundancy = 1
[main-db-server]
description = "Main DB Server"
ssh_command = ssh postgres@127.0.0.1
conninfo = host=127.0.0.1 user=postgres
步骤9：编辑postgresql.conf并启用存档。
在主服务器上进行最后一个配置，以打开备份(或存档)模式。首先，我们需要从 barman 定位传入备份目录的值，切换到用户 barman：
su - barman
运行以下命令以找到传入的备份目录：
barman show-server main | grep incoming_wals_directory
incoming_wals_directory: /home/barman/main/incoming
Note down the value of incoming_wals_directory in my setup it's/home/barman/main/incoming
现在切换到 postgres 服务器上的用户 postgres。
- 打开 postgresql.conf 并对文件进行以下更改： 取消注释 wal_level 参数并将其值设置为存档。 取消注释 archive_mode 参数并将其值设置为 on。 取消注释 archive_command 参数并将其值设置为"rsync -a %p barman@127.0.0.1：/home/barman/main/incoming/%f"。 使用 Barman 服务器的 IP 地址。如果incoming_wals_directory有不同的值。
步骤10：重新启动服务器或实例。
pg_ctl -D /home/postgres/master restart
步骤11：现在登录到酒保(su - 酒保)并检查酒保是否可以连接到postgres。
Barman check main
注意：这里的"main"是在barman.conf中声明的postgres实例的名称。
[barman@localhost ~]$ barman check main
Server main:
PostgreSQL: OK
archive_mode: OK
wal_level: OK
archive_command: OK
continuous archiving: OK
directories: OK
retention policy settings: OK
backup maximum age: OK (no last_backup_maximum_age provided)
compression settings: OK
minimum redundancy requirements: FAILED (have 0 backups, expected at least 1)
ssh: OK (PostgreSQL server)
not in recovery: OK
Step12 ： 以下命令给出 postgres 服务器的信息
[barman@localhost ~]$ barman show-server main
Server main:
active: True
archive_command: false
archive_mode: on
archived_count: 0
backup_directory: /home/barman/main
backup_options: BackupOptions(['exclusive_backup'])
bandwidth_limit: None
basebackup_retry_sleep: 30
basebackup_retry_times: 0
basebackups_directory: /home/barman/main/base
compression: None
config_file: /home/postgres/data/postgresql.conf
conninfo: host=127.0.0.1 user=postgres port=5432
copy_method: rsync
current_archived_wals_per_second: 0.0
current_xlog: 000000010000000000000043
custom_compression_filter: None
custom_decompression_filter: None
data_directory: /home/postgres/data
description: Main PostgreSQL Database
disabled: False
failed_count: 0
步骤13：使用调酒师对主菜进行第一次完整备份
[barman@localhost ~]$ barman backup main
Starting backup for server main in /home/barman/main/base/20160226T134115
Backup start at xlog location: 0/48000028 (000000010000000000000048, 00000028)
Copying files.
Copy done.
Asking PostgreSQL server to finalize the backup.
Backup size: 480.8 MiB. Actual size on disk: 480.8 MiB (-0.00% deduplication ratio).
Backup end at xlog location: 0/480000C0 (000000010000000000000048, 000000C0)
Backup completed
Processing xlog segments for main
Older than first backup. Trashing file 000000010000000000000047 from server main
000000010000000000000048
000000010000000000000048.00000028.backup
Step14 ： 登录到postgres并创建数据库和表，将数据插入表中，然后使用barman(登录到barman)对main进行增量备份。
将数据添加到帖子：
[postgres@localhost ~]$ psql
psql (9.5.1)
Type "help" for help.
postgres=# dt
List of relations
Schema | Name | Type | Owner
--------+------------------+-------+----------
public | pgbench_accounts | table | postgres
public | pgbench_branches | table | postgres
public | pgbench_history | table | postgres
public | pgbench_tellers | table | postgres
public | test | table | postgres
public | test1 | table | postgres
public | test2 | table | postgres
public | test4 | table | postgres
public | test5 | table | postgres
public | test6 | table | postgres
(10 rows)
postgres=# create database test;
CREATE DATABASE
postgres=# c test
You are now connected to database "test" as user "postgres".
test=# create table test1(i int);
CREATE TABLE
test=# create table test2(i int);
CREATE TABLE
test=# insert into test1 values (generate_series(1,1000));
INSERT 0 1000
test=# insert into test2 values (generate_series(1,1000));
INSERT 0 1000
test=# q
Now take incremental backup using barman :
[barman@localhost ~]$ barman backup --reuse=link main
Starting backup for server main in /home/barman/main/base/20160226T134400
Backup start at xlog location: 0/4A000028 (00000001000000000000004A, 00000028)
Copying files.
Copy done.
Asking PostgreSQL server to finalize the backup.
Backup size: 488.0 MiB. Actual size on disk: 7.3 MiB (-98.50% deduplication ratio).
Backup end at xlog location: 0/4A0000C0 (00000001000000000000004A, 000000C0)
Backup completed
Processing xlog segments for main
000000010000000000000049
00000001000000000000004A
00000001000000000000004A.00000028.backup
注意：--重用=链接用于链接主全量备份。这将仅备份从主(postgres)修改或更改的文件。
步骤15：要列出背，请按照以下步骤操作
[barman@localhost ~]$ barman list-backup main
main 20160226T134400 - Fri Feb 26 13:44:07 2016 - Size: 504.0 MiB - WAL Size: 0 B
main 20160226T134115 - Fri Feb 26 13:41:29 2016 - Size: 496.8 MiB - WAL Size: 32.0 MiB
There are two backups listed 20160226T134400 is incremental backup and 20160226T134115 is full backup.
步骤16：现在让我们从备份中恢复
[barman@localhost ~]$ barman recover main 20160226T134400 /tmp/data
Starting local restore for server main using backup 20160226T134400
Destination directory: /tmp/data
Copying the base backup.
Copying required WAL segments.
Generating archive status files
Identify dangerous settings in destination directory.
IMPORTANT
These settings have been modified to prevent data losses
postgresql.conf line 209: archive_command = false
Your PostgreSQL server has been successfully prepared for recovery!
备份在位置/tmp/data 恢复，在恢复时用户必须提供最新的备份 ID
barman recover main latest /tmp/data
步骤17：现在将/tmp/data的所有者更改为"postgres"并启动恢复的实例。
[root@localhost tmp]# chown -R postgres:postgres data
[root@localhost data]# ls -lrth
total 156K
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_twophase
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_tblspc
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_snapshots
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_serial
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_replslot
drwx------. 4 postgres postgres 4.0K Feb 26 08:11 pg_multixact
drwx------. 4 postgres postgres 4.0K Feb 26 08:11 pg_logical
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_dynshmem
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_commit_ts
-rw-------. 1 postgres postgres 4 Feb 26 08:11 PG_VERSION
-rw-------. 1 postgres postgres 88 Feb 26 08:11 postgresql.auto.conf.origin
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_subtrans
-rw-------. 1 postgres postgres 1.6K Feb 26 08:11 pg_ident.conf
drwx------. 2 postgres postgres 4.0K Feb 26 08:11 pg_clog
-rw-------. 1 postgres postgres 4.4K Feb 26 08:27 pg_hba.conf
-rw-------. 1 postgres postgres 22K Feb 26 13:40 postgresql.conf.origin
drwx------. 2 postgres postgres 4.0K Feb 26 13:40 pg_stat
drwx------. 7 postgres postgres 4.0K Feb 26 13:42 base
-rw-------. 1 postgres postgres 224 Feb 26 13:44 backup_label.old
-rw-------. 1 postgres postgres 22K Feb 26 13:45 postgresql.conf
-rw-------. 1 postgres postgres 88 Feb 26 13:45 postgresql.auto.conf
-rw-------. 1 postgres postgres 58 Feb 26 13:46 postmaster.pid
drwx------. 2 postgres postgres 4.0K Feb 26 13:46 pg_notify
-rw-------. 1 postgres postgres 40 Feb 26 13:46 postmaster.opts
drwx------. 2 postgres postgres 4.0K Feb 26 13:46 pg_log
drwx------. 3 postgres postgres 4.0K Feb 26 13:46 pg_xlog
drwx------. 2 postgres postgres 4.0K Feb 26 13:46 global
drwx------. 2 postgres postgres 4.0K Feb 26 13:53 pg_stat_tmp
[root@localhost tmp]# su - postgres
[postgres@localhost ~]$ pg_ctl -D master/ stop
waiting for server to shut down.... done
server stopped
[postgres@localhost ~]$ pg_ctl -D /tmp/data/ start
server starting
[postgres@localhost ~]$ LOG: redirecting log output to logging collector process
HINT: Future log output will appear in directory "pg_log".
psql 到新实例，该实例使用位置/tmp/data 的 barman 恢复。
[postgres@localhost ~]$ psql
psql (9.5.1)
Type "help" for help.
postgres=# dt
List of relations
Schema | Name | Type | Owner
--------+------------------+-------+----------
public | pgbench_accounts | table | postgres
public | pgbench_branches | table | postgres
public | pgbench_history | table | postgres
public | pgbench_tellers | table | postgres
public | test | table | postgres
public | test1 | table | postgres
public | test2 | table | postgres
public | test4 | table | postgres
public | test5 | table | postgres
public | test6 | table | postgres
(10 rows)
postgres=# l+
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges | Size | Tablespace | Description
-----------+----------+----------+-------------+-------------+-----------------------+---------+------------+--------------------------------------------
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 466 MB | pg_default | default administrative connection database
template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +| 7129 kB | pg_default | unmodifiable empty database
| | | | | postgres=CTc/postgres | | |
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +| 7129 kB | pg_default | default template for new databases
| | | | | postgres=CTc/postgres | | |
test | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 7265 kB | pg_default |
(4 rows)
postgres=# c test
You are now connected to database "test" as user "postgres".
test=# dt
List of relations
Schema | Name | Type | Owner
--------+-------+-------+----------
public | test1 | table | postgres
public | test2 | table | postgres
(2 rows)
test=# select count(*) from test1;
count
-------
1000
(1 row)
test=# show data_directory ;
data_directory
----------------
/tmp/data
(1 row)
test=#