Command line backup.
Copy all files to a backup directory
Copy all the files (including the .htaccess file) from your Drupal directory to the backup directory:
The option -rp means copy recursive and preserve permissions.
Put files in compressed archive
Alternatively, you can archive and compress all the files (including the .htaccess file) from your Drupal directory to the backup directory. From your Drupal directory execute:
If you want to check to make sure this worked use tar xzf drupalbackup.tgz to extract the files into a new directory.
Back up database
Before making a database backup, it is recommended to turn off cron jobs.
Mysqldump lets you create a copy of the database: