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.
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
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 $PGDATA/pg_wal/00000010.history 7 0/27000000 no recovery target specified 8 0/2A0012E8 no recovery target specified 12 0/32000000 no recovery target specified 14 0/39A63BD0 no recovery target specified 15 0/40A63B08 no recovery target specified [xdb@localhost ~]$
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