详细的说明~
其中最大的不足在于MySQLdump备份数据库，会锁定所有的表，无法写入，
如果数据库比较大，就是一件很悲剧的事情。
今天介绍一下使用 percona 的xtrabackup 快速且无锁表地建立mysql主从体系。
在mysql 中创建用户的步骤就都略过了。
安装xtrabackup:
rpm -Uhv http://www.percona.com/downloads/percona-release/percona-release-0.0-1.x86_64.rpm
这个是64位的。
32位的地址是：
http://www.percona.com/downloads/percona-release/percona-release-0.0-1.i386.rpm
如果装了这个套装之后却找不到innobackupex命令。。。就。。。：
http://www.percona.com/software/percona-xtrabackup/downloads/
mkdir /data/backup -p
确保在my.cnf中存在[mysqld]
并且在[mysqld]后面存在 datadir = ....
[root@localhost ~]# innobackupex --user=root --password=123456 --defaults-file=/etc/my.cnf /data/backup
InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012. All Rights Reserved.
This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.
120419 10:46:26 innobackupex: Starting mysql with options: --defaults-file='/etc/my.cnf' --password=xxxxxxxx --user='root' --unbuffered --
120419 10:46:26 innobackupex: Connected to database with mysql child process (pid=4394)
120419 10:46:32 innobackupex: Connection to database server closed
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".
innobackupex: Using mysql Ver 14.14 Distrib 5.1.58, for RedHat-linux-gnu (i686) using readline 5.1
innobackupex: Using mysql server version Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
innobackupex: Created backup directory /data/backup/2012-04-19_10-46-32
120419 10:46:32 innobackupex: Starting mysql with options: --defaults-file='/etc/my.cnf' --password=xxxxxxxx --user='root' --unbuffered --
120419 10:46:32 innobackupex: Connected to database with mysql child process (pid=4418)
120419 10:46:34 innobackupex: Connection to database server closed
120419 10:46:34 innobackupex: Starting ibbackup with command: xtrabackup_51 --defaults-file="/etc/my.cnf" --backup --suspend-at-end --target-dir=/data/backup/2012-04-19_10-46-32
innobackupex: Waiting for ibbackup (pid=4426) to suspend
innobackupex: Suspend file '/data/backup/2012-04-19_10-46-32/xtrabackup_suspended'
xtrabackup_51 version 2.0.0 for MySQL server 5.1.59 pc-linux-gnu (i686) (revision id: 417)
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /var/lib/mysql
xtrabackup: Target instance is assumed as followings.
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 5242880
>> log scanned up to (0 9651018)
[01] Copying ./ibdata1 to /data/backup/2012-04-19_10-46-32/ibdata1
[01] ...done
120419 10:46:38 innobackupex: Continuing after ibbackup has suspended
120419 10:46:38 innobackupex: Starting mysql with options: --defaults-file='/etc/my.cnf' --password=xxxxxxxx --user='root' --unbuffered --
120419 10:46:38 innobackupex: Connected to database with mysql child process (pid=4434)
>> log scanned up to (0 9651018)
120419 10:46:40 innobackupex: Starting to lock all tables...
>> log scanned up to (0 9651018)
>> log scanned up to (0 9651018)
120419 10:46:50 innobackupex: All tables locked and flushed to disk
120419 10:46:50 innobackupex: Starting to backup .frm, .MRG, .MYD, .MYI,
innobackupex: .TRG, .TRN, .ARM, .ARZ, .CSM, .CSV and .opt files in
innobackupex: subdirectories of '/var/lib/mysql'
innobackupex: Backing up files '/var/lib/mysql/shipincon/*.{frm,MYD,MYI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (14 files)
innobackupex: Backing up file '/var/lib/mysql/test/t.MYI'
innobackupex: Backing up file '/var/lib/mysql/test/t.MYD'
innobackupex: Backing up file '/var/lib/mysql/test/t.frm'
innobackupex: Backing up files '/var/lib/mysql/mysql/*.{frm,MYD,MYI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (54 files)
120419 10:46:50 innobackupex: Finished backing up .frm, .MRG, .MYD, .MYI, .TRG, .TRN, .ARM, .ARZ, .CSV, .CSM and .opt files
innobackupex: Resuming ibbackup
xtrabackup: The latest check point (for incremental): '0:9651018'
xtrabackup: Stopping log copying thread.
.>> log scanned up to (0 9651018)
xtrabackup: Transaction log of lsn (0 9651018) to (0 9651018) was copied.
120419 10:46:53 innobackupex: All tables unlocked
120419 10:46:53 innobackupex: Connection to database server closed
innobackupex: Backup created in directory '/data/backup/2012-04-19_10-46-32'
innobackupex: MySQL binlog position: filename 'log_bin.000027', position 2973624
120419 10:46:53 innobackupex: completed OK!
最后输出 completed OK! 表示备份成功了。
可以看到在备份myisam类型表的时候，还是会锁表~~ innodb就不会锁表。哼。
备份好的文件保存在 /data/backup目录中，比如：
/data/backup/2012-04-19_10-46-32/
[root@localhost ~]# ls /data/backup/2012-04-19_10-46-32/
backup-my.cnf ibdata1 mysql shipincon test xtrabackup_binary xtrabackup_binlog_info xtrabackup_checkpoints xtrabackup_logfile
备份日志：
刚刚备份好的数据文件，并不是直接可用的。大概是处于一种数据库挂掉的状态~~~，
细节不讲了，要用日志对其进行恢复：
[root@localhost ~]# innobackupex --apply-log /data/backup/2012-04-19_10-46-32/
这个过程与数据库挂掉之后重启mysqld时的自动修复过程差不多。
把数据复制到从服务器：
$ scp -r /data/backup/2012-04-19_10-46-32/ root@newslave:/data/
关闭从服务器并切换数据：
$ /etc/init.d/mysql stop
$ cd /data
$ mv mysql mysql_old
$ mv 2012-04-19_10-46-32 mysql
修改my.cnf， 给它一个独一无二的server_id。
一个比较好的办法是用服务器的IP地址，把其中的.去掉即可。
然后启动mysqld:
$ /etc/init.d/mysql start
最后change master。
与mysqldump备份的步骤比起来，这次我们没有flush tables with read lock，
也没有show master status来获取日志文件名和座标。
因为xtrabackup完成备份之后，自动保存了这些信息。
$ cat /data/mysql/xtrabackup_binlog_info
log_bin.000027 2973624
mysql> CHANGE master to-> master_user=’rep’,-> master_password=’rep’,
-> master_host=’10.20.30.40′,
-> master_log_file=’log_bin.000027′,
-> master_log_pos= 2973624;
然后 start slave 即可。
推荐利用xtrabackup实现从服务器的部署~ 速度真的很快~
