OS : fedora 18
工作流程:
第一次實驗:
數據庫:PostgreSQL9.0.13
1、修改配置文件 postgresql.conf
archive_mode = on
archive_command = 'cp -i %p /home/sure/mywork/archive/%f'
wal_level = hot_standby
2、啓動數據庫
我是在初始化之後,直接修改的數據庫,進而直接啓動數據庫的。
./pg_ctl -D ../data -l logfile start
3、基於文件級別的持續備份
a.模擬數據
CREATE TABLE tab1(a1 int);
INSERT INTO tab1 VALUES (1),(2),(3);
b.備份
postgres=# SELECT now();
now
-------------------------------
2013-11-21 13:35:12.493791+08
(1 row)
postgres=# select pg_start_backup('bak_ws_2013-11-21 13:35:12');
pg_start_backup
-----------------
0/2000020
(1 row)
c.打包data
tar -cvzf data.tar data
d.結束並切換歸檔
postgres=# select pg_stop_backup();
NOTICE: pg_stop_backup complete, all required WAL segments have been archived
pg_stop_backup
----------------
0/20000D8
(1 row)
postgres=# select pg_switch_xlog();
pg_switch_xlog
----------------
0/3000000
(1 row)
這時會再data下產生一個backup_label的文件,記錄了可以查看內容有checkpoint時間,基礎備份的開始和結束時間,以及標籤名稱等。例如這樣:
START WAL LOCATION: 0/2000020 (file 000000010000000000000002)
STOP WAL LOCATION: 0/20000D8 (file 000000010000000000000002)
CHECKPOINT LOCATION: 0/2000058
START TIME: 2013-11-21 13:35:40 CST
LABEL: bak_ws_2013-11-21 13:35:12
STOP TIME: 2013-11-21 13:36:17 CST
e.再次插入數據
postgres=# CREATE TABLE tab2(a1 int);
CREATE TABLE
postgres=# INSERT INTO tab2 VALUES (1),(2),(3);
INSERT 0 3
4、模擬毀壞並進行恢復
a.結束PG服務
postgres=# \q
$ ./pg_ctl -D ../data stop
waiting for server to shut down.... done
server stopped
b.模擬數據庫毀壞
rm -rf data
c.恢復備份文件data.tar
$ tar xvf data.tar
d.刪除pg_xlog文件夾並重建
$ rm -rf pg_xlog
$ mkdir -p pg_xlog/archive_status
e.拷貝recovery.conf文件並修改
我的文件是這樣的:
restore_command = 'cp /home/sure/mywork/archivedir/%f "%p"'
archive_cleanup_command='pg_archivecleanup /home/sure/mywork/archivedir %r'
recovery_target_time='2013-11-21 13:35:12'
recovery_target_time這是用戶自行設定的,如果不寫則會恢復到之前接收到的最後一個歸檔文件。
f.重啓數據庫查看恢復結果
[sure@localhost bin]$ ./pg_ctl -D ../data -l logfile3 start
server starting
[sure@localhost bin]$ ./psql postgres sure
psql (9.0.13)
Type "help" for help.
postgres=# \d
List of relations
Schema | Name | Type | Owner
--------+------+-------+-------
public | tab1 | table | sure
(1 row)
我在此僅恢復到第一次模擬數據(即3.a)。下面是我未寫recovery_target_time的結果:
$ ./pg_ctl -D ../data -l logfile4 start
server starting
$ ./psql postgres sure
psql (9.0.13)
Type "help" for help.
postgres=# \d
List of relations
Schema | Name | Type | Owner
--------+------+-------+-------
public | tab1 | table | sure
public | tab2 | table | sure
(2 rows)
postgres=# SELECT * from tab2;
a1
----
1
2
3
(3 rows)
注:結束後,recovery.conf會改名變成recovery.done。
要注意的是,如果恢復過一次,並設置時間點,下次直接修改recovery_target_time,不會發生效果。
原地址:http://bbs.pgsqldb.com:8079/client/post_show.php?zt_auto_bh=59379