There are multiple instances of MySQL Server running on a single OS that is backed up using the mysqlbackupcommand.
The /etc/my/cnf contains default values, for example, datadir=/var/lib/mysql/,with extra instances having their own separate my.cnffile (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?