昨天在做MySQL 5.6 xtrabackup 增量备份测试的时候，遇见下面的错误，搞了大半个下午都没与解决，度娘也没有给出解决方案，问了大牛，也没给出。
今天早上到公司，去到官网，把官方的文档看了一篇，还好看得懂英文的，这才解决了。
[root@BIDEVEDW_DB bin]# ./xtrabackup --backup --log-stream --target-dir=/mysqlbak/xtrabackup/delta --incremental-basedir=/mysqlbak/xtrabackup/base
xtrabackup: Error: cannot open /mysqlbak/xtrabackup/base/xtrabackup_checkpoints
xtrabackup: error: failed to read metadata from /mysqlbak/xtrabackup/base/xtrabackup_checkpoints
这是全量备份的命令：
./xtrabackup --backup --log-stream --target-dir=/mysqlbak/xtrabackup/20141022 --datadir=/usr/local/mysql/data
1、在做增量备份的时候，如果--target-dir跟全量的一样，就会出现下面的报错
[root@zhanglin bin]# ./xtrabackup --backup --log-stream --target-dir=/mysqlbak/xtrabackup/20141022 --datadir=/usr/local/mysql/data --incremental-basedir=/mysqlbak/xtrabackup/20141022_full_in
xtrabackup: Error: cannot open /mysqlbak/xtrabackup/20141022_full_in/xtrabackup_checkpoints
xtrabackup: error: failed to read metadata from /mysqlbak/xtrabackup/20141022_full_in/xtrabackup_checkpoints
2、 如果--incremental-basedir= 参数的最后目录不是base也会出错。
[root@zhanglin bin]# ./xtrabackup --backup --log-stream --target-dir=/mysqlbak/xtrabackup/20141022_full_in --datadir=/usr/local/mysql/data --incremental-basedir=/mysqlbak/xtrabackup/20141022-test
xtrabackup: Error: cannot open /mysqlbak/xtrabackup/20141022-test/xtrabackup_checkpoints
xtrabackup: error: failed to read metadata from /mysqlbak/xtrabackup/20141022-test/xtrabackup_checkpoints