MySQL数据库的备份，一直是个比较头痛的问题。各种工具虽然不少，但一个真正好用易用的，却又非常难找。Mysqldump做为数据的逻辑备份工具还行，但是无法进行在线热备，而没有物理备份工具，在数据量比较大的时候，恢复的时间也会长得无法接受。InnoDB倒是有个商业的InnoDB Hotbackup，可以对InnoDB引擎的表实现在线热备。最近发现了一个工具，percona出品的Xtrabackup，是InnoDB Hotbackup的一个开源替代品，可以在线对InnoDB/XtraDB引擎的表进行物理备份，试用了一下，非常的不错，值得向MySQL DBA们推荐。
下面是一个实际备份的例子，采用了gzip将备份流进行压缩，约20GB的数据库，压缩后大小为340MB，当然，压缩后的大小跟数据库中实际使用的空间是相关的。备份时间约6分44秒。
innobackupex是参考了InnoDB Hotbackup的innoback脚本修改而来的，主要是为了方便的同时备份InnoDB和MyISAM引擎的表，并且加入了一些使用的选项。如–slave-info可以记录备份恢复后，作为slave需要的一些信息，根据这些信息，可以很方便的利用备份来重做slave。
注意，从备份后的tar包解包的时候，需要使用-i参数。最新发布的是0.7版，猛击这里下载
$innobackupex-1.5.1 –user=root –stream=tar /bak/ –slave-info | gzip > /bak/bak_mysql.tar.gz
InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy.
All Rights Reserved.This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackup
prints “innobackup completed OK!”.innobackupex: Using mysql Ver 14.12 Distrib 5.0.67, for redhat-linux-gnu (x86_64)
using EditLine wrapper
innobackupex: Using mysql server version 5.0.67-loginnobackupex: Created backup directory /bak
090625 15:23:00 innobackupex: Starting mysql with options: –unbuffered –user=root
090625 15:23:00 innobackupex: Connected to database with mysql child process (pid=3431)
090625 15:23:04 innobackupex: Connection to database server closed090625 15:23:04 innobackupex: Starting ibbackup with command:
xtrabackup –backup –suspend-at-end –log-stream –target-dir=./
innobackupex: Waiting for ibbackup (pid=3565) to suspend
innobackupex: Suspend file ‘/opt/mysqldata/xtrabackup_suspended’xtrabackup: suspend-at-end is enabled.
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /opt/mysqldata
xtrabackup: Target instance is assumed as followings.
xtrabackup: innodb_data_home_dir = /opt/mysqldata
xtrabackup: innodb_data_file_path = ibdata1:10G;ibdata2:10G
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 4
xtrabackup: innodb_log_file_size = 104857600
xtrabackup: use O_DIRECT
xtrabackup: Stream mode.
>> log scanned up to (0 3053406941)090625 15:23:06 innobackupex: Continuing after ibbackup has suspended
innobackupex: Starting to backup InnoDB tables and indexes
innobackupex: from original InnoDB data directory ‘/opt/mysqldata’
innobackupex: Backing up as tar stream ‘ibdata1′
>> log scanned up to (0 3053416714)
…这里省略若干行
>> log scanned up to (0 3054123851)
tar: ibdata1: file changed as we read it
innobackupex: Backing up as tar stream ‘ibdata2′
>> log scanned up to (0 3054142116)
…这里省略若干行
>> log scanned up to (0 3054618483)
innobackupex: Backing up file ‘/opt/mysqldata/test/sp.ibd’
innobackupex: Backing up file ‘/opt/mysqldata/test/tmp_dy.ibd’
innobackupex: Backing up files ‘/opt/mysqldata/testdb/*.ibd’ (206 files)
>> log scanned up to (0 3054638401)
>> log scanned up to (0 3054668860)
tar: testdb/group_group_thread_0027.ibd: file changed as we read it
>> log scanned up to (0 3054695015)
>> log scanned up to (0 3054928216)
tar: testdb/group_thread_reply_0007.ibd: file changed as we read it
>> log scanned up to (0 3054952588)
>> log scanned up to (0 3055005439)
tar: testdb/group_user_0001.ibd: file changed as we read it
>> log scanned up to (0 3055028610)
>> log scanned up to (0 3055044650)
tar: testdb/group_user_0006.ibd: file changed as we read it
>> log scanned up to (0 3055060461)
innobackupex: Backing up file ‘/opt/mysqldata/testdb/comments.ibd’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/testdb.ibd’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/testdb_content.ibd’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/testdb_ids.ibd’
090625 15:29:17 innobackupex: Starting mysql with options: –unbuffered –user=root
090625 15:29:17 innobackupex: Connected to database with mysql child process (pid=5458)
>> log scanned up to (0 3055072495)
090625 15:29:21 innobackupex: Starting to lock all tables…
>> log scanned up to (0 3055087148)
>> log scanned up to (0 3055119993)
090625 15:29:39 innobackupex: All tables locked and flushed to disk090625 15:29:39 innobackupex: Starting to backup .frm, .MRG, .MYD, .MYI,
innobackupex: .TRG, .TRN, and .opt files in
innobackupex: subdirectories of ‘/opt/mysqldata’
innobackupex: Backing up file ‘/opt/mysqldata/test/sp.frm’
innobackupex: Backing up file ‘/opt/mysqldata/test/tmp_dy.frm’
innobackupex: Backing up files ‘/opt/mysqldata/testdb/*.{frm,MYD,MYI,MRG,TRG,TRN,opt}’ (207 files)
innobackupex: Backing up file ‘/opt/mysqldata/testdb/comments.frm’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/testdb.frm’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/testdb_content.frm’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/testdb_ids.frm’
innobackupex: Backing up file ‘/opt/mysqldata/testdb/db.opt’
innobackupex: Backing up files ‘/opt/mysqldata/mysql/*.{frm,MYD,MYI,MRG,TRG,TRN,opt}’ (52 files)
090625 15:29:40 innobackupex: Finished backing up .frm, .MRG, .MYD, .MYI, .TRG, .TRN, and .opt filesinnobackupex: Resuming ibbackup
xtrabackup: The latest check point (for incremental): ’0:3054881736′
>> log scanned up to (0 3055120013)
xtrabackup: Transaction log of lsn (0 3053102766) to (0 3055120013) was copied.
090625 15:29:44 innobackupex: All tables unlocked
090625 15:29:44 innobackupex: Connection to database server closedinnobackupex: Backup created in directory ‘/bak/’
innobackupex: MySQL binlog position: filename ”, position
innobackupex: MySQL slave binlog position: master host ’127.0.0.1′,
filename ‘mysql-bin.000006′, position 227207755
090625 15:29:44 innobackupex: innobackup completed OK!
innobackupex: You must use -i (–ignore-zeros) option for extraction of the tar stream.