Xtrabackup是MySQL数据库的备份不可多得的工具之一。提供了全备,增备,数据库级别,表级别备份等等。最牛X的还有不落盘的备份,即流备份方式。对于服务器上空间不足,或是搭建主从,直接使用流式备份大大简化了备份后的压缩复制所带来的更多开销。Xtrabackup支持tar格式以及xbstream格式的流备份。本文即是对此展开的相关描述。
1、基于tar格式备份 a、备份到本地 # innobackupex --stream=tar /tmp >/backup/bak.tar ###非压缩方式 # innobackupex --stream=tar /tmp |gzip >/backup/bakz.tar.gz ###压缩方式 # ls -hltr total 42M -rw-r--r-- 1 root root 39M Apr 15 17:23 bak.tar -rw-r--r-- 1 root root 3.3M Apr 15 17:24 bakz.tar.gz
###解压备份 # mkdir bak bakz # tar -xivf bak.tar -C /backup/bak # tar -xizvf bakz.tar.gz -C /backup/bakz # du -sh * 38M bak 39M bak.tar 38M bakz 3.3M bakz.tar.gz
b、备份到远程 # innobackupex --stream=tar /tmp | ssh root@192.168.1.7 \ "cat - > /backup/bak.tar" ###非压缩方式 # innobackupex --stream=tar /tmp | ssh root@192.168.1.7 \ "gzip >/backup/bak.tar.gz" ###压缩方式
2、使用xbstream格式备份 a、备份到本地 # innobackupex --stream=xbstream /tmp >/backup/bak.xbstream ###非压缩方式 # innobackupex --stream=xbstream --compress /tmp >/backup/bak_compress.xbstream ###压缩方式 # ls -hltr total 43M -rw-r--r-- 1 root root 37M Apr 15 17:41 bak.xbstream -rw-r--r-- 1 root root 6.0M Apr 15 17:41 bak_compress.xbstream
###解压备份 # mkdir bk bk_compress # xbstream -x < bak.xbstream -C /backup/bk ###解压xbstream格式
###解压xbstream格式,compress参数的备份 # xbstream -x < bak_compress.xbstream -C /backup/bk_compress ###首先解压xbstream # for bf in `find . -iname "*\.qp"`; do qpress -d $bf $(dirname $bf) && rm $bf; done ###再解压qp压缩格式 # innobackupex --decompress /backup/bk_compress ###如果xtrabackup版本大于2.1.4,可以直接通过该方式解压
b、备份到远程 ###使用压缩备份到远程并解压 # innobackupex --stream=xbstream --compress /tmp | ssh root@192.168.1.7 "xbstream -x -C /backup/stream"
3、流备份的全备与增备 ###全备数据库,使用--extra-lsndir参数生产checkpoints文件 # innobackupex --stream=xbstream --compress --extra-lsndir=/backup/chkpoint /tmp >/backup/bak_compress.xbstream # more /backup/chkpoint/xtrabackup_checkpoints backup_type = full-backuped from_lsn = 0 to_lsn = 8408290 last_lsn = 8408290 compact = 0
### Author : Leshami ### Blog : http://blog.csdn.net/leshami ###增备数据库,如果后续还需要再次增备,则可以再次指定--extra-lsndir,如果与上次备份指定相同的位置,该文件被覆盖 # innobackupex --compress --incremental --extra-lsndir=/backup/chkpoint --incremental-basedir=/backup/chkpoint \ > --stream=xbstream /tmp >/backup/bak_compress_inc.xbstream
4、流备份的异机恢复 ###备份到异机 # innobackupex --stream=xbstream --extra-lsndir=/backup/chkpoint /tmp | ssh root@192.168.1.7 "xbstream -x -C /backup/stream" # innobackupex --incremental --extra-lsndir=/backup/chkpoint --incremental-basedir=/backup/chkpoint --stream=xbstream \ > /tmp | ssh root@192.168.1.7 "xbstream -x -C /backup/stream_inc"
###异机恢复,copy-back及后续步骤省略 # innobackupex --apply-log --redo-only /backup/stream # innobackupex --apply-log /backup/stream --incremental-dir=/backup/stream_inc
5、其它注意事项 a、如果使用xbstream格式异机备份时,异机未安装xbstream(封装在xtrabackup中)则出现如下错误提示。 bash: xbstream: command not found xtrabackup: Error writing file 'UNOPENED' (Errcode: 32 - Broken pipe) xb_stream_write_data() failed. compress: write to the destination stream failed. xtrabackup: Error writing file 'UNOPENED' (Errcode: 32 - Broken pipe) xb_stream_write_data() failed. xtrabackup: Error writing file 'UNOPENED' (Errcode: 32 - Broken pipe) [01] xtrabackup: Error: xtrabackup_copy_datafile() failed. [01] xtrabackup: Error: failed to copy datafile. innobackupex: Error: The xtrabackup child process has died at /usr/bin/innobackupex line 2681.
b、异机备份时需要建立等效性,如下示例 # ssh-keygen Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /root/.ssh/id_rsa. Your public key has been saved in /root/.ssh/id_rsa.pub. The key fingerprint is: 29:45:ee:8d:b3:55:f1:5f:2f:da:2a:88:0c:0d:37:9f root@vdbsrv1 ###copy 公钥到远程主机 # ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.1.7 21 The authenticity of host '192.168.1.7 (192.168.1.7)' can't be established. RSA key fingerprint is 1d:7c:40:98:ef:de:6f:b8:8c:b2:87:72:0e:79:db:0a. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.1.7' (RSA) to the list of known hosts. root@192.168.1.7's password: Now try logging into the machine, with "ssh 'root@192.168.1.7'", and check in: .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting. ###验证等效性是否成功 # ssh 192.168.1.7 date; Wed Apr 15 17:55:31 CST 2015
c、使用tar格式远程增量备份时收到如下提示,即只支持xbstream xtrabackup: error: streaming incremental backups are incompatible with the 'tar' streaming format. Use --stream=xbstream instead.
d、用流备份,默认的临时目录都是系统的/tmp目录,需要保证该目录有足够的空间,或指定--tmpdir选项
e、流备份日志输出 innobackupex --stream=xbstream /tmp 2>>"$backupLog" | gzip > "$backup_file" 2>>"$backupLog"
6、更多参考