There are different possibilities. If you have access to the machine where mysql is running, you should use:
mysqlhotcopy
On our RedHat 8 server you just type:
/usr/bin/mysqlhotcopy --user=root --password=sdjksjd journal /path/to/backup/directory
Alternatively:
/usr/local/mysql/bin/mysqldump --user=username -p phpgedview >phpgedview
The path of the command is specific for the mysql install on a MacOS X machine.
If you want to back up from another machine you can use the mysqldump command: mysqldump --host=hostname_or_ipaddress --user=username -p phpgedview >phpgedview
This example backs up the database phpgedview which is on the machine hostname_or_ipaddress.
The actual database files are in subdirectories in /var/lib/mysql in case you don't remember their names.
To automatically backup a database via the network you can put a file with the following content to the /etc/cron.hourly directory:
!/bin/sh mysqldump --host=hostname_or_ipaddress --user=USER -pPASSWORD journal >mysqldump_journal
This would create every hour a fresh backupfile called mysqldump_journal in the /etc/cron.hourly directory.