学会4种备份MySQL数据库(基本备份方面没问题了)
前言
为什么需要备份数据?
数据的备份类型
MySQL备份数据的方式
备份需要考虑的问题
设计合适的备份策略
实战演练
使用cp进行备份
查看数据库的信息
mysql> SHOW DATABASES; #查看当前的数据库, 我们的数据库为employees
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
mysql> USE employees;
Database changed
mysql> SHOW TABLES; #查看当前库中的表
+---------------------+
| Tables_in_employees |
+---------------------+
| departments |
| dept_emp |
| dept_manager |
| employees |
| salaries |
| titles |
+---------------------+
6 rows in set (0.00 sec)
mysql> SELECT COUNT(*) FROM employees; #由于篇幅原因, 我们这里只看一下employees的行数为300024
+----------+
| COUNT(*) |
+----------+
| 300024 |
+----------+
1 row in set (0.05 sec)
向数据库施加读锁
mysql> FLUSH TABLES WITH READ LOCK; #向所有表施加读锁
Query OK, 0 rows affected (0.00 sec)
备份数据文件
[root@node1 ~]# mkdir /backup #创建文件夹存放备份数据库文件
[root@node1 ~]# cp -a /var/lib/mysql/* /backup #保留权限的拷贝源数据文件
[root@node1 ~]# ls /backup #查看目录下的文件
employees ibdata1 ib_logfile0 ib_logfile1 mysql mysql.sock test
模拟数据丢失并恢复
[root@node1 ~]# rm -rf /var/lib/mysql/* #删除数据库的所有文件
[root@node1 ~]# service mysqld restart #重启MySQL, 如果是编译安装的应该不能启动, 如果rpm安装则会重新初始化数据库
mysql> SHOW DATABASES; #因为我们是rpm安装的, 连接到MySQL进行查看, 发现数据丢失了!
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)
[root@node1 ~]# rm -rf /var/lib/mysql/* #这一步可以不做
[root@node1 ~]# cp -a /backup/* /var/lib/mysql/ #将备份的数据文件拷贝回去
[root@node1 ~]# service mysqld restart #重启MySQL
#重新连接数据并查看
mysql> SHOW DATABASES; #数据库已恢复
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
mysql> USE employees;
mysql> SELECT COUNT(*) FROM employees; #表的行数没有变化
+----------+
| COUNT(*) |
+----------+
| 300024 |
+----------+
1 row in set (0.06 sec)
##完成
使用mysqldump+复制BINARY LOG备份
mysqldump命令介绍
#基本语法格式 shell> mysqldump [options] db_name [tbl_name ...] 恢复需要手动CRATE DATABASES shell> mysqldump [options] --databases db_name ... 恢复不需要手动创建数据库 shell> mysqldump [options] --all-databases 恢复不需要手动创建数据库
其他选项:
-E, --events: 备份事件调度器
-R, --routines: 备份存储过程和存储函数
--triggers: 备份表的触发器; --skip-triggers
--master-date[=value]
1: 记录为CHANGE MASTER TO 语句、语句不被注释
2: 记录为注释的CHANGE MASTER TO语句
基于二进制还原只能全库还原
--flush-logs: 日志滚动
锁定表完成后执行日志滚动
查看数据库的信息
mysql> SHOW DATABASES; #查看当前的数据库, 我们的数据库为employees
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
mysql> USE employees;
Database changed
mysql> SHOW TABLES; #查看当前库中的表
+---------------------+
| Tables_in_employees |
+---------------------+
| departments |
| dept_emp |
| dept_manager |
| employees |
| salaries |
| titles |
+---------------------+
6 rows in set (0.00 sec)
mysql> SELECT COUNT(*) FROM employees; #由于篇幅原因, 我们这里只看一下employees的行数为300024
+----------+
| COUNT(*) |
+----------+
| 300024 |
+----------+
1 row in set (0.05 sec)
使用mysqldump备份数据库
[root@node1 ~]# mysql -uroot -p -e 'SHOW MASTER STATUS' #查看当前二进制文件的状态, 并记录下position的数字
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000003 | 106 | | |
+------------------+----------+--------------+------------------+
[root@node1 ~]# mysqldump --all-databases --lock-all-tables > backup.sql #备份数据库到backup.sql文件中
mysql> CREATE DATABASE TEST1; #创建一个数据库
Query OK, 1 row affected (0.00 sec)
mysql> SHOW MASTER STATUS; #记下现在的position
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000003 | 191 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
[root@node1 ~]# cp /var/lib/mysql/mysql-bin.000003 /root #备份二进制文件
[root@node1 ~]# service mysqld stop #停止MySQL
[root@node1 ~]# rm -rf /var/lib/mysql/* #删除所有的数据文件
[root@node1 ~]# service mysqld start #启动MySQL, 如果是编译安装的应该不能启动(需重新初始化), 如果rpm安装则会重新初始化数据库
mysql> SHOW DATABASES; #查看数据库, 数据丢失!
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)
mysql> SET sql_log_bin=OFF; #暂时先将二进制日志关闭
Query OK, 0 rows affected (0.00 sec)
mysql> source backup.sql #恢复数据,所需时间根据数据库时间大小而定
mysql> SET sql_log_bin=ON; 开启二进制日志
mysql> SHOW DATABASES; #数据库恢复, 但是缺少TEST1
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
[root@node1 ~]# mysqlbinlog --start-position=106 --stop-position=191 mysql-bin.000003 | mysql employees #通过二进制日志增量恢复数据
mysql> SHOW DATABASES; #现在TEST1出现了!
+--------------------+
| Database |
+--------------------+
| information_schema |
| TEST1 |
| employees |
| mysql |
| test |
+--------------------+
5 rows in set (0.00 sec)
#完成
使用lvm2快照备份数据
部署lvm环境
添加硬盘; 这里我们直接实现SCSI硬盘的热插拔, 首先在虚拟机中添加一块硬盘, 不重启
[root@node1 ~]# ls /dev/sd* #只有以下几块硬盘, 但是我们不重启可以让系统识别新添加的硬盘
/dev/sda /dev/sda1 /dev/sda2
[root@node1 ~]# echo '- - -' > /sys/class/scsi_host/host0/scan
[root@node1 ~]# echo '- - -' > /sys/class/scsi_host/host1/scan
[root@node1 ~]# echo '- - -' > /sys/class/scsi_host/host2/scan
[root@node1 ~]# ls /dev/sd* #看!sdb识别出来了
/dev/sda /dev/sda1 /dev/sda2 /dev/sdb
[root@node1 ~]# fdisk /dev/sdb #分区
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xd353d192.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-2610, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-2610, default 2610): +15G
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
You have new mail in /var/spool/mail/root
[root@node1 ~]# partx -a /dev/sdb BLKPG: Device or resource busy
error adding partition 1 ##创建逻辑卷
[root@node1 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created
[root@node1 ~]# vgcreate myvg /dev/sdb1
Volume group "myvg" successfully created
[root@node1 ~]# lvcreate -n mydata -L 5G myvg
Logical volume "mydata" created.
[root@node1 ~]# mkfs.ext4 /dev/mapper/myvg-mydata #格式化
[root@node1 ~]# mkdir /lvm_data
[root@node1 ~]# mount /dev/mapper/myvg-mydata /lvm_data #挂载到/lvm_data
[root@node1 ~]# vim /etc/my.cnf #修改mysql配置文件的datadir如下
datadir=/lvm_data
[root@node1 ~]# service mysqld restart #重启MySQL ####重新导入employees数据库########略过####
查看数据库的信息
mysql> SHOW DATABASES; #查看当前的数据库, 我们的数据库为employees
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
mysql> USE employees;
Database changed
mysql> SHOW TABLES; #查看当前库中的表
+---------------------+
| Tables_in_employees |
+---------------------+
| departments |
| dept_emp |
| dept_manager |
| employees |
| salaries |
| titles |
+---------------------+
6 rows in set (0.00 sec)
mysql> SELECT COUNT(*) FROM employees; #由于篇幅原因, 我们这里只看一下employees的行数为300024
+----------+
| COUNT(*) |
+----------+
| 300024 |
+----------+
1 row in set (0.05 sec)
创建快照卷并备份
mysql> FLUSH TABLES WITH READ LOCK; #锁定所有表
Query OK, 0 rows affected (0.00 sec)
[root@node1 lvm_data]# lvcreate -L 1G -n mydata-snap -p r -s /dev/mapper/myvg-mydata #创建快照卷
Logical volume "mydata-snap" created.
mysql> UNLOCK TABLES; #解锁所有表
Query OK, 0 rows affected (0.00 sec)
[root@node1 lvm_data]# mkdir /lvm_snap #创建文件夹
[root@node1 lvm_data]# mount /dev/myvg/mydata-snap /lvm_snap/ #挂载snap
mount: block device /dev/mapper/myvg-mydata--snap is write-protected, mounting read-only
[root@node1 lvm_data]# cd /lvm_snap/
[root@node1 lvm_snap]# ls
employees ibdata1 ib_logfile0 ib_logfile1 mysql mysql-bin.000001 mysql-bin.000002 mysql-bin.000003 mysql-bin.index test
[root@node1 lvm_snap]# tar cf /tmp/mysqlback.tar * #打包文件到/tmp/mysqlback.tar
[root@node1 ~]# umount /lvm_snap/ #卸载snap
[root@node1 ~]# lvremove myvg mydata-snap #删除snap
恢复数据
[root@node1 lvm_snap]# rm -rf /lvm_data/*
[root@node1 ~]# service mysqld start #启动MySQL, 如果是编译安装的应该不能启动(需重新初始化), 如果rpm安装则会重新初始化数据库
mysql> SHOW DATABASES; #查看数据库, 数据丢失!
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)
[root@node1 ~]# cd /lvm_data/
[root@node1 lvm_data]# rm -rf * #删除所有文件
[root@node1 lvm_data]# tar xf /tmp/mysqlback.tar #解压备份数据库到此文件夹
[root@node1 lvm_data]# ls #查看当前的文件
employees ibdata1 ib_logfile0 ib_logfile1 mysql mysql-bin.000001 mysql-bin.000002 mysql-bin.000003 mysql-bin.index test
mysql> SHOW DATABASES; #数据恢复了
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)
##完成
使用Xtrabackup备份
下载安装xtrabackup
我们这里通过wget percona官方的rpm包进行安装
[root@node1 ~]# wget https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.3.4/binary/redhat/6/x86_64/percona-xtrabackup-2.3.4-1.el6.x86_64.rpm
[root@node1 ~]# yum localinstall percona-xtrabackup-2.3.4-1.el6.x86_64.rpm #需要EPEL源
xtrabackup介绍
xtrabackup实现完全备份
备份过程
[root@node1 ~]# mkdir /extrabackup #创建备份目录
[root@node1 ~]# innobackupex --user=root /extrabackup/ #备份数据 ###################提示complete表示成功*********************
[root@node1 ~]# ls /extrabackup/ #看到备份目录 2016-04-27_07-30-48
[root@node1 ~]# innobackupex --apply-log /extrabackup/2016-04-27_07-30-48/ #指定备份文件的目录 #一般情况下下面三行结尾代表成功*****************
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number 369661462 160427 07:40:11 completed OK!
[root@node1 ~]# cd /extrabackup/2016-04-27_07-30-48/
[root@node1 2016-04-27_07-30-48]# ls -hl #查看备份文件
total 31M
-rw-r----- 1 root root 386 Apr 27 07:30 backup-my.cnf
drwx------ 2 root root 4.0K Apr 27 07:30 employees
-rw-r----- 1 root root 18M Apr 27 07:40 ibdata1
-rw-r--r-- 1 root root 5.0M Apr 27 07:40 ib_logfile0
-rw-r--r-- 1 root root 5.0M Apr 27 07:40 ib_logfile1
drwx------ 2 root root 4.0K Apr 27 07:30 mysql
drwx------ 2 root root 4.0K Apr 27 07:30 performance_schema
drwx------ 2 root root 4.0K Apr 27 07:30 test
-rw-r----- 1 root root 27 Apr 27 07:30 xtrabackup_binlog_info
-rw-r--r-- 1 root root 29 Apr 27 07:40 xtrabackup_binlog_pos_innodb
-rw-r----- 1 root root 117 Apr 27 07:40 xtrabackup_checkpoints
-rw-r----- 1 root root 470 Apr 27 07:30 xtrabackup_info
-rw-r----- 1 root root 2.0M Apr 27 07:40 xtrabackup_logfile
恢复数据
[root@node1 ~]# rm -rf /data/* #删除数据文件 ***不用启动数据库也可以还原*************
[root@node1 ~]# innobackupex --copy-back /extrabackup/2016-04-27_07-30-48/ #恢复数据, 记清使用方法 #########我们这里是编译安装的mariadb所以需要做一些操作##########
[root@node1 data]# killall mysqld
[root@node1 ~]# chown -R mysql:mysql ./*
[root@node1 ~]# ll /data/ #数据恢复
total 28704
-rw-rw---- 1 mysql mysql 16384 Apr 27 07:43 aria_log.00000001
-rw-rw---- 1 mysql mysql 52 Apr 27 07:43 aria_log_control
-rw-rw---- 1 mysql mysql 18874368 Apr 27 07:43 ibdata1
-rw-rw---- 1 mysql mysql 5242880 Apr 27 07:43 ib_logfile0
-rw-rw---- 1 mysql mysql 5242880 Apr 27 07:43 ib_logfile1
-rw-rw---- 1 mysql mysql 264 Apr 27 07:43 mysql-bin.000001
-rw-rw---- 1 mysql mysql 19 Apr 27 07:43 mysql-bin.index
-rw-r----- 1 mysql mysql 2166 Apr 27 07:43 node1.anyisalin.com.err
[root@node1 data]# service mysqld restart
MySQL server PID file could not be found! [FAILED]
Starting MySQL.. [ OK ]
MariaDB [(none)]> SHOW DATABASES; #查看数据库, 已经恢复
+--------------------+
| Database |
+--------------------+
| information_schema |
| employees |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.00 sec
增量备份
#########创建连两个数据库以供测试#####################
MariaDB [(none)]> CREATE DATABASE TEST1;
Query OK, 1 row affected (0.00 sec)
MariaDB [(none)]> CREATE DATABASE TEST2;
Query OK, 1 row affected (0.00 sec)
[root@node1 ~]# innobackupex --incremental /extrabackup/ --incremental-basedir=/extrabackup/2016-04-27_07-30-48/
[root@node1 ~]# ls /extrabackup/2016-04-27_07-57-22/ #查看备份文件
total 96
-rw-r----- 1 root root 386 Apr 27 07:57 backup-my.cnf
drwx------ 2 root root 4096 Apr 27 07:57 employees
-rw-r----- 1 root root 49152 Apr 27 07:57 ibdata1.delta
-rw-r----- 1 root root 44 Apr 27 07:57 ibdata1.meta
drwx------ 2 root root 4096 Apr 27 07:57 mysql
drwx------ 2 root root 4096 Apr 27 07:57 performance_schema
drwx------ 2 root root 4096 Apr 27 07:57 test
drwx------ 2 root root 4096 Apr 27 07:57 TEST1
drwx------ 2 root root 4096 Apr 27 07:57 TEST2
-rw-r----- 1 root root 21 Apr 27 07:57 xtrabackup_binlog_info
-rw-r----- 1 root root 123 Apr 27 07:57 xtrabackup_checkpoints
-rw-r----- 1 root root 530 Apr 27 07:57 xtrabackup_info
-rw-r----- 1 root root 2560 Apr 27 07:57 xtrabackup_logfile
整理增量备份
[root@node1 ~]# innobackupex --apply-log --redo-only /extrabackup/2016-04-27_07-30-48/
[root@node1 ~]# innobackupex --apply-log --redo-only /extrabackup/2016-04-27_07-30-48/ --incremental-dir=/extrabackup/2016-04-27_07-5 7-22/
恢复数据
[root@node1 ~]# rm -rf /data/* #删除数据
[root@node1 ~]# innobackupex --copy-back /extrabackup/2016-04-27_07-30-48/ #整理增量备份之后可以直接通过全量备份还原
[root@node1 ~]# chown -R mysql.mysql /data/
[root@node1 ~]# ls /data/ -l total 28732
-rw-rw---- 1 mysql mysql 8192 Apr 27 08:05 aria_log.00000001
-rw-rw---- 1 mysql mysql 52 Apr 27 08:05 aria_log_control drwx------ 2 mysql mysql 4096 Apr 27 08:05 employees
-rw-r----- 1 mysql mysql 18874368 Apr 27 08:05 ibdata1
-rw-r----- 1 mysql mysql 5242880 Apr 27 08:05 ib_logfile0
-rw-r----- 1 mysql mysql 5242880 Apr 27 08:05 ib_logfile1 drwx------ 2 mysql mysql 4096 Apr 27 08:05 mysql
-rw-rw---- 1 mysql mysql 245 Apr 27 08:05 mysql-bin.000001
-rw-rw---- 1 mysql mysql 19 Apr 27 08:05 mysql-bin.index
-rw-r----- 1 mysql mysql 1812 Apr 27 08:05 node1.anyisalin.com.err
-rw-rw---- 1 mysql mysql 5 Apr 27 08:05 node1.anyisalin.com.pid drwx------ 2 mysql mysql 4096 Apr 27 08:05 performance_schema drwx------ 2 mysql mysql 4096 Apr 27 08:05 test drwx------ 2 mysql mysql 4096 Apr 27 08:05 TEST1 drwx------ 2 mysql mysql 4096 Apr 27 08:05 TEST2
-rw-r----- 1 mysql mysql 29 Apr 27 08:05 xtrabackup_binlog_pos_innodb
-rw-r----- 1 mysql mysql 530 Apr 27 08:05 xtrabackup_info MariaDB [(none)]> SHOW DATABASES; #数据还原
+--------------------+
| Database |
+--------------------+
| information_schema |
| TEST1 |
| TEST2 |
| employees |
| mysql |
| performance_schema |
| test |
+--------------------+ 7 rows in set (0.00 sec) #关于xtrabackup还有很多强大的功能没有叙述、有兴趣可以去看官方文档
总结
备份方法 | 备份速度 | 恢复速度 | 便捷性 | 功能 | 一般用于 |
---|---|---|---|---|---|
cp | 快 | 快 | 一般、灵活性低 | 很弱 | 少量数据备份 |
mysqldump | 慢 | 慢 | 一般、可无视存储引擎的差异 | 一般 | 中小型数据量的备份 |
lvm2快照 | 快 | 快 | 一般、支持几乎热备、速度快 | 一般 | 中小型数据量的备份 |
xtrabackup | 较快 | 较快 | 实现innodb热备、对存储引擎有要求 | 强大 | 较大规模的备份 |