You have been tasked with creating a QA MySQL instance on a DB host, which already has one large instance in /var/lib/mysql/running as the mysqluser. The MySQL configuration file for the existing instance includes:

The default instance was installed using the OS package manager. The latest binaries for both client and server are already in ENV PATH.
The new instance will run as a different user from the existing instance for security purposes.
You create the new data directory successfully and move on to initialize the new DATADIR.
You verify the output to confirm the operation's success:
[mysqlQA@linux /var/lib/]$ mysqld --initialize --datadir=/var/lib/mysql_QA 2>&1 | tail -n3
2018-05-03T12:16:10.928809Z 0 [ERROR] Could not open file '/var/log/mysqld.log' for error logging:
Permission denied
2018-05-03T12:16:10.928841Z 0 [ERROR] Aborting
[mysqlQA@linux /var/lib/]$
The initialization of the instance has failed.
What would you do to enable the initialization to succeed?

A MySQL database uses all InnoDB tables and is configured as follows;

You will be setting up a replication slave by using mysqldump. You will need a consistent backup taken from your running production server. The process should have minimal impact to active database connections.
Which two arguments will you pass to mysqldump to achieve this? (Choose two.)

An administrator installs MySQL to run under a mysqlOS account. The administrator decides to disable logins to the mysqlaccount by using /nologinor /bin/falseas the user's shell setting.
Which statement is true?

Is it true that binary backups always take less space than text backups?

Consider the index information for the dept_emp table in the employee's schema:

Which two conclusions can be made based on the output of the query?