用一句話概括冷備,就是把數據庫服務,比如MySQL,Oracle停下來,然後使用拷貝、打包或者壓縮命令對數據目錄進行備份。如果數據出現異常,則可以通過備份數據恢復。冷備一般需要定制計劃,比如什麼時候做備份,每次對哪些數據進行備份等等。但是由於這樣的備份占用過多的空間,對大數據量的環境下不一定適合,故生產環境很少使用。
冷備示意圖
冷備實驗
第一步,創建測試數據庫,插入測試數據
mysql> use larrydb; Database changed mysql> show tables; +-------------------+ | Tables_in_larrydb | +-------------------+ | access | +-------------------+ 1 row in set (0.00 sec) mysql> drop table access; Query OK, 0 rows affected (0.00 sec) mysql> clear mysql> show tables; Empty set (0.00 sec) mysql> mysql> create table class( -> cid int, -> cname varchar(30)); Query OK, 0 rows affected (0.01 sec) mysql> show create table class \G; *************************** 1. row *************************** Table: class Create Table: CREATE TABLE `class` ( `cid` int(11) DEFAULT NULL, `cname` varchar(30) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 1 row in set (0.00 sec) ERROR: No query specified mysql> create table stu( -> sid int, -> sname varchar(30), -> cid int) engine=myisam; Query OK, 0 rows affected (0.00 sec) mysql> show create table stu \G; *************************** 1. row *************************** Table: stu Create Table: CREATE TABLE `stu` ( `sid` int(11) DEFAULT NULL, `sname` varchar(30) DEFAULT NULL, `cid` int(11) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=utf8 1 row in set (0.00 sec) ERROR: No query specified mysql> insert into class values(1,'linux'),(2,'oracle'); Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> desc class; +-------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+-------+ | cid | int(11) | YES | | NULL | | | cname | varchar(30) | YES | | NULL | | +-------+-------------+------+-----+---------+-------+ 2 rows in set (0.00 sec) mysql> desc stu; +-------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+-------+ | sid | int(11) | YES | | NULL | | | sname | varchar(30) | YES | | NULL | | | cid | int(11) | YES | | NULL | | +-------+-------------+------+-----+---------+-------+ 3 rows in set (0.00 sec) mysql> insert into stu values(1,'larry01',1),(2,'larry02',2); Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from stu; +------+---------+------+ | sid | sname | cid | +------+---------+------+ | 1 | larry01 | 1 | | 2 | larry02 | 2 | +------+---------+------+
第二步,停掉MySQL
[root@serv01 ~]# /etc/init.d/mysqld stop Shutting down MySQL... SUCCESS!
第三步,創建備份目錄,並修改擁有者和所屬組
[root@serv01 ~]# mkdir /databackup [root@serv01 ~]# chown mysql.mysql /databackup/ -R [root@serv01 ~]# ll /databackup/ -d drwxr-xr-x. 2 mysql mysql 4096 Sep 10 17:46 /databackup/ [root@serv01 ~]# cd /databackup/
第四步,冷備(使用tar命令)
[root@serv01 databackup]# tar -cvPzf mysql01.tar.gz
第五步,測試冷備的數據是否正常,我們刪除掉data下的所有數據
[root@serv01 databackup]# rm -rf /usr/local/mysql/data/*
第六步,刪除所有數據後數據庫不能啟動
[root@serv01 databackup]# /etc/init.d/mysqld start Starting MySQL.. ERROR! The server quit without updating PID file (/usr/local/mysql/data/serv01.host.com.pid).
第七步,恢復數據(使用tar命令)
[root@serv01 databackup]# tar -xvPf mysql01.tar.gz
第八步,啟動MySQL,然後登錄MySQL,查看數據是否丟失,如果數據正常代表冷備成功
[root@serv01 databackup]# /etc/init.d/mysqld start Starting MySQL.. SUCCESS! [root@serv01 ~]# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1 Server version: 5.5.29-log Source distribution Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> use larrydb; Database changed mysql> select * from class; +------+--------+ | cid | cname | +------+--------+ | 1 | linux | | 2 | oracle | +------+--------+ 2 rows in set (0.00 sec) mysql> select * from stu; +------+---------+------+ | sid | sname | cid | +------+---------+------+ | 1 | larry01 | 1 | | 2 | larry02 | 2 | +------+---------+------+ 2 rows in set (0.00 sec)
以上就是實現MySQL冷備的全部過程,大家對冷備有沒有了大概的了解,希望這篇文章可以對大家的學習有所幫助。