【物理备份】pg_rman介绍及使用

原创 Asher.Hu 云和恩墨交付战队 2022-02-22

3513

1.pg_rman 介绍

1.1 pg_rman 介绍

• pg_rman类似于oracle的rman备份策略，实现了全量、增量、归档的层级的备份，可以很灵活的管理PostgreSQL数据库的备份，pg_rman是一款开源的pg的备份恢复插件支持在线和基于PITR的备份恢复方式。

• pg_rman特点：
    ○ 使用简单.一个命令即可完成备份和恢复.
    ○ 支持在线全备,增量备份，归档备份.
    ○ 支持备份压缩.通过gzip工具实现页内压缩.
    ○ 自动备份维护.自动删除过期的WAL备份文件.
    ○ 支持备份验证.
    ○ 恢复期间无事务丢失.支持基于PITR的配置文件生成器.


  • pg_rman 注意事项：
    ○  pg_rman 基于 pg_start_backup
    ○  pg_rman 基于 需要在本地安装，不能远程德份
    ○  pg_rman 需要下载对应的版本
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1.2 pg_rman 下载

下载地址：
https://github.com/ossc-db/pg_rman/

PostgreSQL Rpm相关依赖、插件包下载地址：
https://yum.postgresql.org/10/redhat/rhel-6.7-x86_64/

手册地址：
http://ossc-db.github.io/pg_rman/index.html
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2.安装使用


源码包安装方法：

  1、下载源码包

         wget  https://github.com/ossc-db/pg_rman/releases/download/V1.3.7/pg_rman-1.3.7-pg10.tar.gz    

   2、解压到指定目录

         tar -zxvf  pg_rman-1.3.14-pg12.tar.gz -C /opt/

   3、进入到rman目录进行编译安装

         cd /opt/pg_rman-1.3.14-pg12/

         make && make install

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# 设置环境变量：

 PATH=$PATH:$HOME/bin

export PG_RMAN=/u01/postgresql/pg12

export PGHOME=/u01/postgresql/pg12

export PGDATA=/u01/postgresql/data

export PGLIB=/u01/postgresql/pg12/lib

export SRVLOG_PATH=/u01/postgresql/data/log

export ARCLOG_PATH=/u01/postgresql/archive

export BACKUP_PATH=/opt/pg_rman

export PATH=$PGHOME/bin:$PATH:$PG_RMAN/bin

export PATH

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3.pg_rman 使用

3.1 pg_rman的用法

pg_rman的使用相对简单核心8个命令

pg_rman manage backup/recovery of PostgreSQL database.

Usage:

  pg_rman OPTION init

  pg_rman OPTION backup

  pg_rman OPTION restore

  pg_rman OPTION show [DATE]

  pg_rman OPTION show detail [DATE]

  pg_rman OPTION validate [DATE]

  pg_rman OPTION delete DATE

  pg_rman OPTION purge

init      初始化备份目录
backup    在线备份
restore   恢复
show      查看备份历史
validate  验证备份
delete    删除备份文件
purge     从备份目录中删除已删除备份
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3.2 初始化备份目录

首先需要初始化一个backup catalog，目录将用于存放备份的文件，目录也会存放一些元数据，例如备份的配置文件，数据库的systemid，时间线文件历史   

注意：在初始化的时候，要先确认环境变量是否设置正确。

root@mxl ~]# pg_rman init -B /opt/pg_rman

总用量 8

drwx------ 4 root root 35 11月 23 13:30 backup

-rw-r--r-- 1 root root 83 11月 23 13:30 pg_rman.ini

-rw-r--r-- 1 root root 40 11月 23 13:30 system_identifier

drwx------ 2 root root  6 11月 23 13:30 timeline_history
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3.3 查看pg_rman的配置文件信息

[postgres@mxl pg_rman]$ cat pg_rman.ini 



ARCLOG_PATH=‘/home/postgres/arch’                        --归档目录

SRVLOG_PATH=‘/home/postgres/data/log’                   --数据库错误日志目录

COMPRESS_DATA = YES                                   --压缩数据

KEEP_ARCLOG_FILES = 10                                 --保存归档文件个数

KEEP_ARCLOG_DAYS = 10                                  --保存归档的天数

KEEP_DATA_GENERATIONS = 3                               --备份冗余度

KEEP_DATA_DAYS = 10                                   --保存备份集时间

KEEP_SRVLOG_FILES = 10                                 --保存日志文件个数

KEEP_SRVLOG_DAYS = 10                                  --保存日志文件天数
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3.4 pg_rman的全量备份

如果没有调设置export BACKUP_PATH=/opt/pg_rman  ，需要手动指明备份路径 --backup-path=/opt/pg_rman

postgres@s2ahumysqlpg01-> pg_rman backup --backup-mode=full --with-serverlog  -h 127.0.0.1

INFO: copying database files

INFO: copying archived WAL files

INFO: copying server log files

INFO: backup complete

INFO: Please execute 'pg_rman validate' to verify the files are correctly copied.



一、pg_rman 校验备份集：

postgres@s2ahumysqlpg01-> pg_rman show

=====================================================================

 StartTime           EndTime              Mode    Size   TLI  Status 

=====================================================================

2022-02-22 17:18:39  2022-02-22 17:19:12  FULL   942MB     5  DONE



二、未校验备份集 Status 显示为 DONE，开始校验

[postgres@mxl pg_rman]$ pg_rman validate

INFO: validate: "2019-12-03 11:53:39" backup, archive log files and server log files by CRC

INFO: backup "2019-12-03 11:53:39" is valid

[postgres@mxl pg_rman]$ pg_rman show

=====================================================================

 StartTime           EndTime              Mode    Size   TLI  Status 

=====================================================================

2019-12-03 11:53:39  2018-12-03 11:54:00  FULL   461MB     1  OK



一、pg_rman 备份集查看：

[postgres@mxl pg_rman]$ pg_rman show

=====================================================================

 StartTime           EndTime              Mode    Size   TLI  Status 

=====================================================================

2019-12-03 11:53:39  2019-12-03 11:54:00  FULL   461MB     1  DONE



二、未校验备份集 Status 显示为 DONE，开始校验

postgres@s2ahumysqlpg01-> pg_rman validate

INFO: validate: "2022-02-22 17:18:39" backup, archive log files and server log files by CRC

INFO: backup "2022-02-22 17:18:39" is valid





postgres@s2ahumysqlpg01->  pg_rman show

=====================================================================

 StartTime           EndTime              Mode    Size   TLI  Status 

=====================================================================

2022-02-22 17:18:39  2022-02-22 17:19:12  FULL   942MB     5  OK
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3.5 pg_rman的增量备份

增量备份是基于文件系统的update time时间线，增量备份必须有个对应的全库备份

postgres@s2ahumysqlpg01-> pg_rman backup --backup-mode=incremental --progress --compress-data  -h 127.0.0.1

INFO: copying database files

INFO: copying archived WAL filesipped 3028

Processed 16 of 16 files, skipped 13

INFO: backup complete

INFO: Please execute 'pg_rman validate' to verify the files are correctly copied.



备份集查看：

$ pg_rman show

    postgres@s2ahumysqlpg01-> pg_rman show

=====================================================================

 StartTime           EndTime              Mode    Size   TLI  Status 

=====================================================================

2022-02-22 17:22:54  2022-02-22 17:22:58  INCR    33kB     5  DONE

2022-02-22 17:18:39  2022-02-22 17:19:12  FULL   942MB     5  OK





postgres@s2ahumysqlpg01-> pg_rman validate

INFO: validate: "2022-02-22 17:22:54" backup and archive log files by CRC

INFO: backup "2022-02-22 17:22:54" is valid

postgres@s2ahumysqlpg01-> 

postgres@s2ahumysqlpg01-> 

postgres@s2ahumysqlpg01-> pg_rman show

=====================================================================

 StartTime           EndTime              Mode    Size   TLI  Status 

=====================================================================

2022-02-22 17:22:54  2022-02-22 17:22:58  INCR    33kB     5  OK

2022-02-22 17:18:39  2022-02-22 17:19:12  FULL   942MB     5  OK

postgres@s2ahumysqlpg01-> 
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3.6 pg_rman 归档备份

一、pg_rman 归档备份：

归档备份就是静态文件的拷贝。

$ pg_rman backup --backup-mode=archive --progress --compress-data 

$ pg_rman validate

$ pg_rman show



二、删除备份集

删除备份集指定日期之前的，不需要用来指定时间点之前的备份删除掉

[postgres@mxl ~]$ pg_rman delete " pg_rman delete "2022-02-22 17:22:58""



三、清除备份集

物理删除已从catalog删除的备份集

上面从备份集中删除的备份，备份集文件夹并没有一起删除。

[postgres@mxl ~]$ pg_rman purge
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4 pg_rman 恢复

pg_rman 恢复默认原地恢复（覆盖式），或者使用新的$PGDATA作为恢复目标。需注意如果在本机恢复pg_rman可能会覆盖原有的数据文件arch,pg_xlog目录中的文件, 可以先将原数据文件做下备份,默认pg_rman restore会在$PGDATA下产生recovery.conf根据实际需要修改相关恢复参数即可。 



1、recovery-target-timeline TIMELINE  

Specifies recovering into a particular timeline. If not specified, the current timeline from ($PGDATA/global/pg_control) is used. 

如果不指定时间线，则使用$PGDATA/global/pg_control，如果没有$PGDATA/global/pg_control，则使用最新的全量备份集的时间线。 



2、recovery-target-time TIMESTAMP  

This parameter specifies the time stamp up to which recovery will proceed. If not specified, continue recovery to the latest time.

如果不指定，则恢复到最新时间  



3、recovery-target-xid XID  

This parameter specifies the transaction ID up to which recovery will proceed. If not specified, continue recovery to the latest xid.

如果不指定，则恢复到最新xid



4、recovery-target-inclusive

    Specifies whether we stop just after the specified recovery target (true), or just before the recovery target (false). Default is true. 

    是否在指定的恢复目标（true）之后停止，默认为true，如果指定false意识是在恢复目标之前停止

    

• The following parameter determines the behavior of restore.  

    --hard-copy  

    The archive WAL are copied to archive WAL storage area. If not specified, pg_rman makes symbolic link to archive WAL where are in the backup catalog directory. 

    是否使用硬链接复制archive log，如果不指定使用符号连接（软连接）的方式。
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#示例:  

    #pg_rman restore  --recovery-target-time "2022-02-22 17:25:30";  下面是没有指定的恢复

    [postgres@mxl~]$ pg_rman restore 

    INFO: backup "2022-02-22 17:25:30" is valid

    INFO: the recovery target timeline ID is not given

    INFO: use timeline ID of current database cluster as recovery target: 5

    INFO: calculating timeline branches to be used to recovery target point

    INFO: searching latest full backup which can be used as restore start point

    INFO: found the full backup can be used as base in recovery: "2022-02-22 17:25:30"

    INFO: copying online WAL files and server log files

    INFO: clearing restore destination

    INFO: validate: "2022-02-22 17:25:30" backup, archive log files and server log files by SIZE

    INFO: backup "2022-02-22 17:25:30" is valid

    INFO: restoring database files from the full mode backup "2022-02-22 17:25:30"

    INFO: searching incremental backup to be restored

    INFO: searching backup which contained archived WAL files to be restored

    INFO: backup "2022-02-22 17:25:30" is valid

    INFO: restoring WAL files from backup "2022-02-22 17:25:30"

    INFO: restoring online WAL files and server log files

    INFO: create pg_rman_recovery.conf for recovery-related parameters.

    INFO: remove an 'include' directive added by pg_rman in postgresql.conf if exists

    INFO: append an 'include' directive in postgresql.conf for pg_rman_recovery.conf

    INFO: generating recovery.signal

    INFO: removing standby.signal if exists to restore as primary

    INFO: restore complete

    HINT: Recovery will start automatically when the PostgreSQL server is started. After the recovery is done, we recommend to remove        recovery-related parameters configured by pg_rman.



    pg_ctl start 

    

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