[root@node1 op]#mysql -V
mysql Ver 14.14 Distrib 5.6.29
innobackupex热备份MySQL报错，报错信息：
[root@node1 op]#innobackupex --defaults-file=/data/mysql/my.cnf --user=dba --password= --host=127.0.0.1 --port=3306
180530 10:22:01 innobackupex: Starting the backup operation
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".
180530 10:22:01 version_check Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_group=xtrabackup;host=127.0.0.1;port=3306;mysql_socket=/tmp/mysql.sock' as 'dba' (using password: YES).
180530 10:22:01 version_check Connected to MySQL server
180530 10:22:01 version_check Executing a version check against the server...
180530 10:22:01 version_check Done.
180530 10:22:01 Connecting to MySQL server host: 127.0.0.1, user: dba, password: set, port: 3306, socket: /tmp/mysql.sock
Using server version 5.6.29-log
/opt/scripts/percona-xtrabackup/bin/innobackupex version 2.4.6 based on MySQL server 5.7.13 Linux (x86_64) (revision id: 54967d1)
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /data/mysql/data
xtrabackup: open files limit requested 0, set to 1024
xtrabackup: using the following InnoDB configuration:
xtrabackup: innodb_data_home_dir = /data/mysql/log
xtrabackup: innodb_data_file_path = ibdata1:256M:autoextend
xtrabackup: innodb_log_group_home_dir = /data/mysql/log
xtrabackup: innodb_log_files_in_group = 4
xtrabackup: innodb_log_file_size = 268435456
2018-05-30 10:22:01 0x7f40a5b6f720 InnoDB: Using Linux native AIO
xtrabackup: using O_DIRECT
InnoDB: Number of pools: 1
180530 10:22:01 >> log scanned up to (51650555498)
xtrabackup: Generating a list of tablespaces
InnoDB: Allocated tablespace ID 115 for test/ids, old maximum was 0
InnoDB: Attempted to open a previously opened tablespace. Previous tablespace test/plan at filepath: ./test/plan.ibd uses space ID: 3. Cannot open filepath: ./mysql/slave_relay_log_info.ibd which uses the same space ID.
解决方式：
1. drop these tables from mysql:slave_relay_log_info
2. delete all .frm & .ibd of the tables above.
3. run this file to recreate the tables above (source five-tables.sql).需要提前读出表的定义SQL
4. restart mysqld.