On CentOS 7 Linux it is usually by default
But here I give you another "hacky" way to find it out.
The method is to find out the mysql daemon mysqld' opened files and the paths because it must open the files to read/write data.
First, find out the process ID of the mysqld process:
# ps aux | grep mysqld
mysql 25403 1.0 17.2 1322220 174948 ? Ssl Aug31 178:10 /usr/sbin/mysqld
Second, go to the mysqld process' dir under
/proc/. For the above example,
# cd /proc/25403/
Check the opened files under the directory fd:
# ls fd -lha
An example is as follows for some files:
lrwx------. 1 mysql mysql 64 Sep 12 11:43 83 -> /var/lib/mysql/my_wp2/wp_links.MYI
lrwx------. 1 mysql mysql 64 Sep 12 11:43 84 -> /var/lib/mysql/my_wp2/wp_links.MYD
You get the path for the directory to storing the database data files.