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本篇内容介绍了“怎么恢复 PostgreSQL 数据文件损坏”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让丸趣 TV 小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
在数据文件损坏, 数据库无法正常启动的时候,Oracle 可通过数据库备份 + 归档日志 + 在线日志实现数据库的完整恢复, 与之类似,PostgreSQL 也可以通过数据库备份 + 归档 WAL 日志 + 在线 WAL 日志进行完整恢复.
一、场景
1. 执行备份
2. 构造测试数据
3. 删除数据文件(保留 WAL 日志文件)
4. 使用备份 + 在线 WAL 日志文件进行完整恢复
二、模拟完整恢复
参数配置
archive_mode = on
archive_command = /home/xdb/archive.sh
wal_level = replica
max_wal_size = 4GB
min_wal_size = 1024MB详细请参考
Backup Recovery#1(基本操作)
执行备份
查看当前的 LSN
testdb=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
0/39A63C78
(1 row)使用工具 pg_basebackup 对数据库进行备份
testdb=# \q
[xdb@localhost testdb]$ pg_basebackup -D /data/backup/0312-1/ -l 0312-1 -v -F tar -z
pg_basebackup: initiating base backup, waiting for checkpoint to complete
pg_basebackup: checkpoint completed
pg_basebackup: write-ahead log start point: 0/3A000108 on timeline 15
pg_basebackup: starting background WAL receiver
pg_basebackup: created temporary replication slot pg_basebackup_2978
pg_basebackup: write-ahead log end point: 0/3A0001D8
pg_basebackup: waiting for background process to finish streaming ...
pg_basebackup: base backup completed
[xdb@localhost testdb]$
[xdb@localhost testdb]$ ll /data/backup/0312-1/
total 44384
-rw-------. 1 xdb xdb 45427619 Mar 12 17:30 base.tar.gz
-rw-------. 1 xdb xdb 18927 Mar 12 17:30 pg_wal.tar.gz
[xdb@localhost testdb]$
[xdb@localhost ~]$ psql -d testdb
psql (11.2)
Type help for help.
testdb=# checkpoint;
CHECKPOINT
testdb=#构造测试数据
创建数据表, 插入数据
testdb=# create table tbl01(id int,c1 char(200),c2 char(200));
CREATE TABLE
testdb=# insert into tbl01 select f,f|| c1 ,f|| c2 from generate_series(1,100000) f;
INSERT 0 100000
testdb=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
0/3DD39618
(1 row)
testdb=# create table tbl02(id int,c1 char(200),c2 char(200));
CREATE TABLE
testdb=# insert into tbl02 select f,f|| c1 ,f|| c2 from generate_series(1,100000) f;
INSERT 0 100000
testdb=# select pg_current_wal_lsn();
pg_current_wal_lsn
--------------------
0/40A62F20
(1 row)
testdb=#当前在线日志文件为 0000000F0000000000000040
[xdb@localhost testdb]$ ll $PGDATA/pg_wal
total 196632
-rw-------. 1 xdb xdb 42 Mar 12 17:10 00000008.history
-rw-------. 1 xdb xdb 85 Mar 12 17:10 0000000C.history
-rw-------. 1 xdb xdb 16777216 Mar 12 17:10 0000000E0000000000000039.partial
-rw-------. 1 xdb xdb 129 Mar 12 17:10 0000000E.history
-rw-------. 1 xdb xdb 16777216 Mar 12 17:30 0000000F000000000000003A
-rw-------. 1 xdb xdb 323 Mar 12 17:30 0000000F000000000000003A.00000108.backup
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003B
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003C
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003D
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003E
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003F
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F0000000000000040
-rw-------. 1 xdb xdb 16777216 Mar 12 17:10 0000000F0000000000000041
-rw-------. 1 xdb xdb 16777216 Mar 12 17:10 0000000F0000000000000042
-rw-------. 1 xdb xdb 16777216 Mar 12 17:10 0000000F0000000000000043
-rw-------. 1 xdb xdb 16777216 Mar 12 17:30 0000000F0000000000000044
-rw-------. 1 xdb xdb 173 Mar 12 17:11 0000000F.history
drwx------. 2 xdb xdb 4096 Mar 12 17:32 archive_status
[xdb@localhost testdb]$归档日志文件信息
[xdb@localhost testdb]$ ll /data/archivelog/20190312/
total 245772
-rw-------. 1 xdb xdb 16777216 Mar 12 17:06 0000000E0000000000000032
-rw-------. 1 xdb xdb 16777216 Mar 12 17:06 0000000E0000000000000033
-rw-------. 1 xdb xdb 323 Mar 12 17:06 0000000E0000000000000033.00000028.backup
-rw-------. 1 xdb xdb 16777216 Mar 12 17:07 0000000E0000000000000034
-rw-------. 1 xdb xdb 16777216 Mar 12 17:07 0000000E0000000000000035
-rw-------. 1 xdb xdb 16777216 Mar 12 17:07 0000000E0000000000000036
-rw-------. 1 xdb xdb 16777216 Mar 12 17:07 0000000E0000000000000037
-rw-------. 1 xdb xdb 16777216 Mar 12 17:07 0000000E0000000000000038
-rw-------. 1 xdb xdb 16777216 Mar 12 17:11 0000000E0000000000000039.partial
-rw-------. 1 xdb xdb 16777216 Mar 12 17:30 0000000F0000000000000039
-rw-------. 1 xdb xdb 16777216 Mar 12 17:30 0000000F000000000000003A
-rw-------. 1 xdb xdb 323 Mar 12 17:30 0000000F000000000000003A.00000108.backup
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003B
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003C
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003D
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003E
-rw-------. 1 xdb xdb 16777216 Mar 12 17:32 0000000F000000000000003F
-rw-------. 1 xdb xdb 173 Mar 12 17:11 0000000F.history
[xdb@localhost testdb]$模拟数据文件损坏
删除数据文件目录,kill postgres 进程
[xdb@localhost testdb]$ rm -rf ./base
[xdb@localhost testdb]$ psql -d testdb
psql: FATAL: database testdb does not exist
DETAIL: The database subdirectory base/16384 is missing.
[xdb@localhost testdb]$ ps -ef|grep postgres
xdb 2914 1 0 17:11 pts/2 00:00:00 /appdb/xdb/pg11.2/bin/postgres
xdb 2915 2914 0 17:11 ? 00:00:00 postgres: logger
xdb 2918 2914 0 17:11 ? 00:00:00 postgres: checkpointer
xdb 2919 2914 0 17:11 ? 00:00:00 postgres: background writer
xdb 2921 2914 0 17:11 ? 00:00:00 postgres: stats collector
xdb 2925 2914 0 17:11 ? 00:00:00 postgres: walwriter
xdb 2926 2914 0 17:11 ? 00:00:00 postgres: autovacuum launcher
xdb 2927 2914 0 17:11 ? 00:00:00 postgres: archiver last was 0000000F000000000000003F
xdb 2928 2914 0 17:11 ? 00:00:00 postgres: logical replication launcher
xdb 2977 2914 0 17:30 ? 00:00:00 postgres: xdb testdb [local] idle
xdb 3014 2519 0 17:33 pts/2 00:00:00 grep --color=auto postgres
[xdb@localhost testdb]$ kill -9 2914
[xdb@localhost testdb]$ ps -ef|grep postgres
xdb 3016 2519 0 17:34 pts/2 00:00:00 grep --color=auto postgres执行恢复
备份在线日志
[xdb@localhost ~]$ mkdir /data/backup/wal
[xdb@localhost testdb]$ cp -R ./pg_wal/* /data/backup/wal/
[xdb@localhost testdb]$
[xdb@localhost testdb]$ ll /data/backup/wal/
total 196632
-rw-------. 1 xdb xdb 42 Mar 12 17:34 00000008.history
-rw-------. 1 xdb xdb 85 Mar 12 17:34 0000000C.history
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000E0000000000000039.partial
-rw-------. 1 xdb xdb 129 Mar 12 17:34 0000000E.history
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F000000000000003A
-rw-------. 1 xdb xdb 323 Mar 12 17:34 0000000F000000000000003A.00000108.backup
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F000000000000003B
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F000000000000003C
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F000000000000003D
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F000000000000003E
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F000000000000003F
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F0000000000000040
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F0000000000000041
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F0000000000000042
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F0000000000000043
-rw-------. 1 xdb xdb 16777216 Mar 12 17:34 0000000F0000000000000044
-rw-------. 1 xdb xdb 173 Mar 12 17:34 0000000F.history
drwx------. 2 xdb xdb 4096 Mar 12 17:34 archive_status
[xdb@localhost testdb]$从数据库备份中恢复
[xdb@localhost testdb]$ rm -rf *
[xdb@localhost testdb]$ cp /data/backup/0312-1/base.tar.gz ./
[xdb@localhost testdb]$ tar zxf base.tar.gz恢复在线日志
cp -R /data/backup/wal/0000000F0000000000000040 ./pg_wal
[xdb@localhost testdb]$ ll ./pg_wal
total 16384
-rw-------. 1 xdb xdb 16777216 Mar 12 17:35 0000000F0000000000000040
drwx------. 2 xdb xdb 6 Mar 12 17:30 archive_status创建 recovery.conf 文件
[xdb@localhost testdb]$ vim recovery.conf
[xdb@localhost testdb]$ cat recovery.conf
#Recovery
restore_command= cp /data/archivelog/20190312/%f %p
#restore_target=XX执行恢复, 启动数据库
[xdb@localhost testdb]$ pg_ctl start
waiting for server to start....2019-03-12 17:36:21.310 CST [3030] LOG: listening on IPv4 address 0.0.0.0 , port 5432
2019-03-12 17:36:21.310 CST [3030] LOG: listening on IPv6 address :: , port 5432
2019-03-12 17:36:21.328 CST [3030] LOG: listening on Unix socket /tmp/.s.PGSQL.5432
2019-03-12 17:36:21.341 CST [3030] LOG: redirecting log output to logging collector process
2019-03-12 17:36:21.341 CST [3030] HINT: Future log output will appear in directory pg_log .
done
server started日志输出
2019-03-12 17:36:21.341 CST,,,3030,,5c877d95.bd6,1,,2019-03-12 17:36:21 CST,,0,LOG,00000, ending log output to stderr ,, Future log output will go to log destination csvlog . ,,,,,,,
2019-03-12 17:36:21.350 CST,,,3032,,5c877d95.bd8,1,,2019-03-12 17:36:21 CST,,0,LOG,00000, database system was interrupted; last known up at 2019-03-12 17:30:44 CST ,,,,,,,,,
2019-03-12 17:36:21.358 CST,,,3032,,5c877d95.bd8,2,,2019-03-12 17:36:21 CST,,0,LOG,00000, starting archive recovery ,,,,,,,,,
2019-03-12 17:36:21.372 CST,,,3032,,5c877d95.bd8,3,,2019-03-12 17:36:21 CST,,0,LOG,00000, restored log file 0000000F.history from archive ,,,,,,,,,
2019-03-12 17:36:21.486 CST,,,3032,,5c877d95.bd8,4,,2019-03-12 17:36:21 CST,,0,LOG,00000, restored log file 0000000F000000000000003A from archive ,,,,,,,,,
2019-03-12 17:36:21.693 CST,,,3032,,5c877d95.bd8,5,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, redo starts at 0/3A000108 ,,,,,,,,,
2019-03-12 17:36:21.696 CST,,,3032,,5c877d95.bd8,6,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, consistent recovery state reached at 0/3A0001D8 ,,,,,,,,,
2019-03-12 17:36:21.696 CST,,,3030,,5c877d95.bd6,2,,2019-03-12 17:36:21 CST,,0,LOG,00000, database system is ready to accept read only connections ,,,,,,,,,
2019-03-12 17:36:21.826 CST,,,3032,,5c877d95.bd8,7,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, restored log file 0000000F000000000000003B from archive ,,,,,,,,,
2019-03-12 17:36:22.245 CST,,,3032,,5c877d95.bd8,8,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, restored log file 0000000F000000000000003C from archive ,,,,,,,,,
2019-03-12 17:36:22.614 CST,,,3032,,5c877d95.bd8,9,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, restored log file 0000000F000000000000003D from archive ,,,,,,,,,
2019-03-12 17:36:23.039 CST,,,3032,,5c877d95.bd8,10,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, restored log file 0000000F000000000000003E from archive ,,,,,,,,,
2019-03-12 17:36:23.342 CST,,,3032,,5c877d95.bd8,11,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, restored log file 0000000F000000000000003F from archive ,,,,,,,,,
2019-03-12 17:36:23.874 CST,,,3032,,5c877d95.bd8,12,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, invalid record length at 0/40A63B08: wanted 24, got 0 ,,,,,,,,,
2019-03-12 17:36:23.874 CST,,,3032,,5c877d95.bd8,13,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, redo done at 0/40A63AD0 ,,,,,,,,,
2019-03-12 17:36:23.874 CST,,,3032,,5c877d95.bd8,14,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, last completed transaction was at log time 2019-03-12 17:33:32.760492+08 ,,,,,,,,,
2019-03-12 17:36:23.879 CST,,,3032,,5c877d95.bd8,15,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, selected new timeline ID: 16 ,,,,,,,,,
2019-03-12 17:36:24.773 CST,,,3032,,5c877d95.bd8,16,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, archive recovery complete ,,,,,,,,,
2019-03-12 17:36:24.777 CST,,,3032,,5c877d95.bd8,17,,2019-03-12 17:36:21 CST,1/0,0,LOG,00000, restored log file 0000000F.history from archive ,,,,,,,,,
2019-03-12 17:36:25.589 CST,,,3030,,5c877d95.bd6,3,,2019-03-12 17:36:21 CST,,0,LOG,00000, database system is ready to accept connections ,,,,,,,,,验证数据
[xdb@localhost testdb]$ psql -d testdb
psql (11.2)
Type help for help.
testdb=#
testdb=# select count(*) from tbl01;
count
--------
100000
(1 row)
testdb=# select count(*) from t02;
count
--------
100000
(1 row)
testdb=#时间线历史文件, 在归档目录和 pg_wal 目录下均存在以当前时间线命名的 history, 该文件说明了该 Cluster 的历史.
[xdb@localhost ~]$ cat /data/archivelog/20190312/00000010.history
7 0/27000000 no recovery target specified
8 0/2A0012E8 no recovery target specified
12 0/32000000 no recovery target specified
14 0/39A63BD0 no recovery target specified
15 0/40A63B08 no recovery target specified
[xdb@localhost ~]$ cat $PGDATA/pg_wal/00000010.history
7 0/27000000 no recovery target specified
8 0/2A0012E8 no recovery target specified
12 0/32000000 no recovery target specified
14 0/39A63BD0 no recovery target specified
15 0/40A63B08 no recovery target specified
[xdb@localhost ~]$“怎么恢复 PostgreSQL 数据文件损坏”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注丸趣 TV 网站，丸趣 TV 小编将为大家输出更多高质量的实用文章！
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