Xtrabackup是MySQL資料庫的備份不可多得的工具之一。提供了全備，增備，資料庫級別，表級別備份等等。最牛X的還有不落盤的備份，即流備份方式。對於伺服器上空間不足，或是搭建主從，直接使用流式備份大大簡化了備份後的壓縮複製所帶來的更多開銷。Xtrabackup支援tar格式以及xbstream格式的流備份。本文即是對此展開的相關描述。

1、基於tar格式備份 a、備份到本地 #innobackupex --stream=tar /tmp >/backup/bak.tar ###非壓縮方式 #innobackupex --stream=tar /tmp |gzip >/backup/bakz.tar.gz ###壓縮方式 #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

###解壓備份 #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、備份到遠端 #innobackupex --stream=tar /tmp | ssh [email protected] \ “cat - > /backup/bak.tar” ###非壓縮方式 #innobackupex --stream=tar /tmp | ssh [email protected]

2、使用xbstream格式備份 a、備份到本地 #innobackupex --stream=xbstream /tmp >/backup/bak.xbstream ###非壓縮方式 #innobackupex --stream=xbstream --compress /tmp >/backup/bak_compress.xbstream ###壓縮方式 #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

###解壓備份 #mkdir bk bk_compress #xbstream -x < bak.xbstream -C /backup/bk ###解壓xbstream格式

###解壓xbstream格式，compress引數的備份 #xbstream -x < bak_compress.xbstream -C /backup/bk_compress ###首先解壓xbstream #for bf in find . -iname "*\.qp"; do qpress -d $bf $(dirname $bf) && rm $bf; done ###再解壓qp壓縮格式 #innobackupex --decompress /backup/bk_compress ###如果xtrabackup版本大於2.1.4，可以直接通過該方式解壓

b、備份到遠端 ###使用壓縮備份到遠端並解壓 #innobackupex --stream=xbstream --compress /tmp | ssh [email protected] “xbstream -x -C /backup/stream”

3、流備份的全備與增備 ###全備資料庫，使用–extra-lsndir引數生產checkpoints檔案 #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 ###增備資料庫，如果後續還需要再次增備，則可以再次指定–extra-lsndir，如果與上次備份指定相同的位置，該檔案被覆蓋 #innobackupex --compress --incremental --extra-lsndir=/backup/chkpoint --incremental-basedir=/backup/chkpoint \

–stream=xbstream /tmp >/backup/bak_compress_inc.xbstream

4、流備份的異機恢復 ###備份到異機 #innobackupex --stream=xbstream --extra-lsndir=/backup/chkpoint /tmp | ssh [email protected] “xbstream -x -C /backup/stream” #innobackupex --incremental --extra-lsndir=/backup/chkpoint --incremental-basedir=/backup/chkpoint --stream=xbstream \

/tmp | ssh [email protected] “xbstream -x -C /backup/stream_inc”

###異機恢復，copy-back及後續步驟省略 #innobackupex --apply-log --redo-only /backup/stream #innobackupex --apply-log /backup/stream --incremental-dir=/backup/stream_inc

5、其它注意事項 a、如果使用xbstream格式異機備份時，異機未安裝xbstream(封裝在xtrabackup中)則出現如下錯誤提示。 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、異機備份時需要建立等效性，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 [email protected]

###copy 公鑰到遠端主機 #ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected] 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??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. [email protected]’s password: Now try logging into the machine, with “ssh ‘[email protected]’”, and check in:

.ssh/authorized_keys

to make sure we haven’t added extra keys that you weren’t expecting.

###驗證等效性是否成功 #ssh 192.168.1.7 date; Wed Apr 15 17:55:31 CST 2015

c、使用tar格式遠端增量備份時收到如下提示，即只支援xbstream xtrabackup: error: streaming incremental backups are incompatible with the ‘tar’ streaming format. Use --stream=xbstream instead.

d、用流備份，預設的臨時目錄都是系統的/tmp目錄，需要保證該目錄有足夠的空間，或指定–tmpdir選項

e、流備份日誌輸出 innobackupex --stream=xbstream /tmp 2>>“$backupLog&quot; | gzip &gt; &quot;$backup_file” 2>>"$backupLog"