This method or trick is important when your database crash and you are not able connect to database. Still your will be able to take mysql backup from file system. Many times we fail to restore the mysql dump from command line.
How to take mysql backup from file system
If your mysql server crash. Follow my steps to take mysql backup from file system without database connection.
First go to your filesystem.
Here I am using the fedora OS for this example
In linux go to /var/lib/mysql path
In that folder each folder means separate database.
Copy that all folders to your local machine.
again go to your mysql local installation and paste that folder into your mysql folder.
For in each database folder file you will find following types of files in the folder
db.opt
test.frm
test.MYD
test.MYI