today in the experiment about xtrabackup MySQL does not come up, after the check found to be the issue of permission settings. From this thought in the daily work will appear MySQL can not start the problem, here to build a post, the problems encountered are collected, easy to access.
1, the permissions are not configured
The following are the log messages:
150327 13:06:54mysqld_safe starting mysqld daemon with databases From/usr/local/mysql/data
150327 13:06:55[note] Plugin ' federated ' is disabled.
15032713:06:55 innodb:started; Log SequenceNumber 0 343564
150327 13:06:55[error] Event scheduler:failed to open Table Mysql.event
150327 13:06:55[error] Event scheduler:error while loading from disk.
150327 13:06:55[note] Event scheduler:purging the queue. 0 Events
150327 13:06:55[error] Aborting
15032713:06:55 innodb:starting shutdown ...
15032713:06:56 Innodb:shutdown completed; Logsequence number 0 343564
150327 13:06:56[note]/usr/local/mysql/bin/mysqld:shutdown complete
Workaround:
Chown Mysql:mysql-r/usr/local/mysql/data
chmod 660-r/usr/local/mysql/data
MySQL Start error summary