xtrabackup有两个主要的工具：innobackupex和xtrabackup，xtrabackup只能备份InnoDB和XtraDB数据表，innobackupex封装了xtrabackup，可以备份MyISAM数据表。 MySQL数据库本身提供的工具并不支持真正的增量备份，二进制日志恢复是point-in-time(时间点)的恢复而不是增量备份。Xtrabackup工具支持对InnoDB存储引擎的增量备份，工作原理如下： 1.首先完成一个完全备份，并记录下此时检查点的LSN(Log Sequence Number)。 2.在进程增量备份时，比较表空间中每个页的LSN是否大于上次备份时的LSN，如果是，则备份该页，同时记录当前检查点的LSN。 1.下载xtrabackup（下载二进制版本免安装） # wget # tar zxvf xtrabackup-1.5.tar.gz -C /usr/local/ 源码安装过程具体参见源码目录下BUILD.txt文件。 2.xtrabackup选项注释如下： –print-defaults 显示默认选项。Xtrabackup默认情况会去读my.cnf文件，读取顺序是/etc/my.cnf /etc/mysql/my.cnf /usr/local/etc/my.cnf ~/.my.cnf –no-defaults 忽略任何my.cnf文件选项 –defaults-file=# 读取指定的my.cnf文件 –defaults-extra-file=# 再读取另外一个文件 –target-dir=name 目的目录，默认目录在./xtrabackup_backupfiles/，相对于datadir目录 –backup 备份 –stats 计算datadir目录统计信息 –prepare 从backup恢复 –export 在恢复时，创建文件导入到另一个数据库 –apply-log-only 在恢复时，停止恢复进程不进行LSN只使用log –print-param 打印出参数 –use-memory=# buffer_pool_size值 –suspend-at-end 在备份时，创建xtrabackup_suspended文件，直到备份完成后删掉 –throttle=# 限制IO总数 –log-stream 记录标准输出信息xtrabackup_logfile –extra-lsndir=name 仅适用于backup，保存另一份xtrabackup_checkpoints文件 –incremental-lsn=name 仅适用于backup，增量备份 –incremental-basedir=name 仅适用于backup，增量备份目录 –incremental-dir=name 仅适用于prepare，恢复指定目录下的.delta文件和日志文件 –tables=name 过滤某些表 –tables_file=name 过滤database.table列表文件 –create-ib-logfile -h, –datadir=name datadir目录 -t, –tmpdir=name tmpdir目录 –parallel=# 默认为1.传输数据文件的并行线程数。没有任何流模式的影响 –innodb_* 有关innodb参数 3.innobackupex-1.5.1选项注释如下： innobackupex-1.5.1 [--sleep=MS] [--compress[=LEVEL]] [--include=REGEXP] [--user=NAME] [--password=WORD] [--port=PORT] [--socket=SOCKET] [--no-timestamp] [--ibbackup=IBBACKUP-BINARY] [--slave-info] [--stream=tar] [--scpopt=OPTIONS-FOR-SCP] [--defaults-file=MY.CNF] [--databases=LIST] [--remote-host=HOSTNAME] [--no-lock] BACKUP-ROOT-DIR 对数据库进行热备。默认情况下以当前时间戳创建备份根目录。上述命令完整备份所有MyISAM和InnoDB引擎表以及索引。包含.frm,.MRG, .MYD, .MYI, .TRG, .TRN, .ARM, .ARZ, .opt, .par和InnoDB数据和日志文件。使用mysql客户端程序连接mysql服务器，运行ibbackup(InnoDB热备程序)作为一个子进程。 innobackupex-1.5.1 –apply-log [--use-memory=MB] [--uncompress] [--defaults-file=MY.CNF] [--export] [--redo-only] [--ibbackup=IBBACKUP-BINARY] BACKUP-DIR 从备份恢复，运行ibbackup子进程，但是不能连接到数据库。按照BACKUP-DIR/backup-my.cnf定义，使用BACKUP-DIR/ibbackup_logfile恢复InnoDB数据文件和创建新的InnoDB日志文件。 innobackupex-1.5.1 –copy-back [--defaults-file=MY.CNF] BACKUP-DIR 从备份目录拷贝数据，索引和日志文件到原datadir目录。 –defaults-file=[MY.CNF] 该选项传递给xtrabackup子进程，从指定文件读取缺省选项 –apply-log 从备份恢复。 –redo-only 该选项强制跳过rollback阶段，只进行redo。这是有必要使用的，如果备份后，要使用增量改变的。 –copy-back 从备份目录拷贝数据和索引文件到datadir目录 –remote-host=HOSTNAME 备份到远程主机上，使用ssh –stream=[tar|cpio(not implemented)] 指定备份标准输出格式 –tmpdir=DIRECTORY 默认与tmpdir相同。使用—remote-host或—stream参数后，传输日志文件将存放在临时目录下 –use-memory=MB 选项传递给xtrabackup子进程。恢复使用内存大小 –parallel=NUMBER-OF-THREADS 选项传递给xtrabackup子进程，指定数据传输线程总数。默认为1 –throttle=IOS 选项传递给xtrabackup子进程，限制IO线程数量 –sleep=MS 选项传递给xtrabackup子进程。每拷贝1MB数据暂停多少MS时间 –compress[=LEVEL] 选项传递给xtrabackup子进程。压缩级别在0-9.1快速压缩，9最佳压缩，0不压缩。默认为1. –include=REGEXP选项传递给xtrabackup子进程。使用正则进行匹配 –databases=LIST 指定备份数据库 –tables-file=FILE –uncompress选项传递给xtrabackup子进程。对压缩过的InnoDB数据文件不进行压缩 –export 仅使用于prepare选项。选项传递给xtrabackup子进程。 –user=NAME –password=WORD –host=HOST –port=PORT –slave-info 备份复制从服务端，主从信息记录在ibbackup_slave_info文件中 –socket=SOCKET –no-timestamp 不在备份根目录下创建以当前时间戳为名称的新的备份目录 –ibbackup=IBBACKUP-BINARY ibbackup二进制路径 –no-lock 禁止表级锁。全部是InnoDB引擎表和不关系二进制日志位置下使用 –scpopt=SCP-OPTIONS 指定scp参数 4.innobackupex备份 # ./innobackupex-1.5.1 /www/mybak/ 在/www/mybak/目录下将创建以时间戳为名称的目录 –stream=tar 将使用到tar4ibd进行压缩。注意：在解压时候必须加上-i参数进行解压。 5.恢复 # ./mysqladmin shutdown # rm -rf innodb # ./innobackupex-1.5.1 –apply-log /www/mybak/2011-04-11_15-28-02/ # ./innobackupex-1.5.1 –copy-back /www/mybak/2011-04-11_15-28-02/ # chown –R mysql.mysql /www/mydata 6.xtrabackup备份 # ./xtrabackup –defaults-file=/etc/my.cnf –backup –target-dir=/mydata/mybak/ # ls cacti ibdata1 nagios test xtrabackup_checkpoints xtrabackup_logfile 7.恢复 # ./xtrabackup –defaults-file=/etc/my.cnf –prepare –target-dir=/mydata/mybak/ ./xtrabackup Ver 1.5 Rev undefined for 5.1.53 unknown-linux-gnu (x86_64) xtrabackup: cd to /mydata/mybak/ xtrabackup: This target seems to be not prepared yet. xtrabackup: xtrabackup_logfile detected: size=2097152, start_lsn=(732446480) xtrabackup: Temporary instance for recovery is set 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 = 1 xtrabackup: innodb_log_file_size = 2097152 xtrabackup: Starting InnoDB instance for recovery. xtrabackup: Using 104857600 bytes for buffer pool (set by –use-memory parameter) InnoDB: The InnoDB memory heap is disabled InnoDB: Mutexes and rw_locks use GCC atomic builtins InnoDB: Compressed tables use zlib 1.2.3 InnoDB: Warning: innodb_file_io_threads is deprecated. Please use innodb_read_io_threads and innodb_write_io_threads instead 110411 16:49:25 InnoDB: highest supported file format is Barracuda. InnoDB: Log scan progressed past the checkpoint lsn 732446480 110411 16:49:25 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files… InnoDB: Doing recovery: scanned up to log sequence number 733504186 (56 %) 110411 16:49:25 InnoDB: Starting an apply batch of log records to the database… InnoDB: Progress in percents: 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 InnoDB: Apply batch completed InnoDB: Last MySQL binlog file position 0 560768957, file name ./mysql-bin.000001 110411 16:49:25 Percona XtraDB ( ) 1.0.13-12.4 started; log sequence number 733504186 [notice (again)] If you use binary log and don’t use any hack of group commit, the binary log position seems to be: InnoDB: Last MySQL binlog file position 0 560768957, file name ./mysql-bin.000001 xtrabackup: starting shutdown with innodb_fast_shutdown = 1 110411 16:49:32 InnoDB: Starting shutdown… 110411 16:49:33 InnoDB: Shutdown completed; log sequence number 733553275 # ls cacti ibdata1 nagios test xtrabackup_binlog_pos_innodb xtrabackup_checkpoints xtrabackup_logfile # ./xtrabackup –defaults-file=/etc/my.cnf –prepare –target-dir=/mydata/mybak/ ./xtrabackup Ver 1.5 Rev undefined for 5.1.53 unknown-linux-gnu (x86_64) xtrabackup: cd to /mydata/mybak/ xtrabackup: This target seems to be already prepared. xtrabackup: notice: xtrabackup_logfile was already used to ‘–prepare’. xtrabackup: Temporary instance for recovery is set 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 = 3 xtrabackup: innodb_log_file_size = 268435456 xtrabackup: Starting InnoDB instance for recovery. xtrabackup: Using 104857600 bytes for buffer pool (set by –use-memory parameter) InnoDB: The InnoDB memory heap is disabled InnoDB: Mutexes and rw_locks use GCC atomic builtins InnoDB: Compressed tables use zlib 1.2.3 InnoDB: Warning: innodb_file_io_threads is deprecated. Please use innodb_read_io_threads and innodb_write_io_threads instead 110411 16:49:58 InnoDB: Log file ./ib_logfile0 did not exist: new to be created InnoDB: Setting log file ./ib_logfile0 size to 256 MB InnoDB: Database physically writes the file full: wait… InnoDB: Progress in MB: 100 200 110411 16:50:03 InnoDB: Log file ./ib_logfile1 did not exist: new to be created InnoDB: Setting log file ./ib_logfile1 size to 256 MB InnoDB: Database physically writes the file full: wait… InnoDB: Progress in MB: 100 200 110411 16:50:09 InnoDB: Log file ./ib_logfile2 did not exist: new to be created InnoDB: Setting log file ./ib_logfile2 size to 256 MB InnoDB: Database physically writes the file full: wait… InnoDB: Progress in MB: 100 200 110411 16:50:14 InnoDB: highest supported file format is Barracuda. InnoDB: The log sequence number in ibdata files does not match InnoDB: the log sequence number in the ib_logfiles! 110411 16:50:14 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files… InnoDB: Last MySQL binlog file position 0 560768957, file name ./mysql-bin.000001 110411 16:50:14 Percona XtraDB ( ) 1.0.13-12.4 started; log sequence number 733553676 [notice (again)] If you use binary log and don’t use any hack of group commit, the binary log position seems to be: InnoDB: Last MySQL binlog file position 0 560768957, file name ./mysql-bin.000001 xtrabackup: starting shutdown with innodb_fast_shutdown = 1 110411 16:50:16 InnoDB: Starting shutdown… 110411 16:50:16 InnoDB: Shutdown completed; log sequence number 733553676 # ls cacti ib_logfile0 ib_logfile2 test xtrabackup_checkpoints ibdata1 ib_logfile1 nagios xtrabackup_binlog_pos_innodb xtrabackup_logfile 此时InnoDB的全部数据文件已经恢复了。将这些文件拷贝到datadir目录下。 注意：xtrabackup只是备份数据文件，不会备份数据表结构。因此恢复时，必须有对应的表结构文件。 # cp -r cacti /mydata/data/ # cp -r ib* /mydata/data/ # cp -r nagios /mydata/data/ # chown –R mysql.mysql /mydata/data # /usr/local/mysql-5.5.11/bin/mysqld –user=mysql & 8.增量备份 a.全量备份 # ./xtrabackup –backup –target-dir=/mydata/mybak/base xtrabackup: The latest check point (for incremental): ‘783599510‘ >> log scanned up to (783977887) xtrabackup: Stopping log copying thread. xtrabackup: Transaction log of lsn (783374191) to (783977887) was copied. # ls cacti ibdata1 nagios xtrabackup_checkpoints xtrabackup_logfile # cat xtrabackup_checkpoints backup_type = full-backuped from_lsn = 0 to_lsn = 783599510 last_lsn = 783977887 b.增量备份 # ./xtrabackup –backup –target-dir=/mydata/mybak/delta –incremental-basedir=/mydata/mybak/base incremental backup from 783599510 is enabled. …… xtrabackup: The latest check point (for incremental): ‘793114541‘ >> log scanned up to (795499255) xtrabackup: Stopping log copying thread. xtrabackup: Transaction log of lsn (793069999) to (795499255) was copied. # ls /mydata/mybak/delta/ cacti ibdata1.delta nagios xtrabackup_checkpoints xtrabackup_logfile # cat /mydata/mybak/delta/xtrabackup_checkpoints backup_type = incremental from_lsn = 783599510 to_lsn = 793114541 last_lsn = 795499255 在增量备份目录下，数据文件都是以.delta结尾的。增量备份只备份上一次全量备份之后被修改过的page。 C.恢复过程：需要分别对全量和增量备份进行恢复操作 # ./xtrabackup –prepare –target-dir=/mydata/mybak/base # ./xtrabackup –prepare –target-dir=/mydata/mybak/base –incremental-dir=/mydata/mybak/delta 上述过程，首先将全部文件备份到/mydata/mybak/base目录下，增量备份产生的文件备份到/mydata/mybak/delta目录下。在恢复过程中，首先指定全量备份的路径，然后将增量备份应用于该全量备份。 将/mydata/mybak/base目录下的文件拷贝到datadir目录下，即可。同时还需要数据表结构文件。