10月7號

There are multiple instances of MySQL Server running on a single OS that is backed up using
the mysqlbackup command.
The /etc/my/cnf contains default values, for example, datadir=/var/lib/mysql/, with extra instances
having their own separate my.cnf file (for example /etc/mysql/instanceN.cnf) overriding the defaults.
A restore of the second instance is attempted from the mysqlbackup archive using this command:
mysqlbackup --backup-dir=/opt/backup/mysql/instance2 copy-back
Upon starting the second MySQL instance, you notice that the data does not match the expected
backup. Which command-line option is required to successfully update the second instance?
A. --defaults-file=/etc/mysql/instance2.cnf
B. --copy-back-from-log
C. --restore=2
D. --backup-instance=/var/lib/mysql/instance2
E. --instance=/var/lib/mysql/instance2

解析:mysql的啟動引數預設從/etc/my/cnf取得,如果要使用特定的引數檔案來啟動,需要使用

--defaults-file
Answer: A